Emergency personnel and volunteers have staged a dramatic terror attack drill in London to test the city?s readiness ahead of this summer?s Olympic Games.

A packed train slammed into the end of the line in a Buenos Aires station, killing 49 people and injuring 600 commuters in Argentina's worst train accident in decades.

Cherie Blair, the wife of former Prime Minister Tony Blair, is suing Rupert Murdoch's British newspaper company over phone hacking.

Their canvas is a stretch of dingy concrete wall along Manila's main highway, where millions of vehicles stream past every day, belching exhaust that helps to create a noxious, unhealthy smog.

Two U.S. helicopters have arrived in Montenegro to join rescue operations in the areas of the tiny Balkan state hit by the heaviest snowfall in 60 years.

City will never be the same again, mayor says.

Reuters - The U.N. nuclear watchdog ended its latest mission to Iran after talks on Tehran's suspected secret atomic weapons research failed, a setback likely to increase the risk of confrontation with the West.

Perrin told Libération that the press centre, which had a generator and a patchy internet connection, was the only means of informing the outside world of what was happening in the city. "If the press centre were destroyed, there would be no more information out of Homs."

Perrin said the Syrian army recommended "killing any journalist that stepped on Syrian soil". He said the journalists had been aware of this, and of reports of intercepted communications between Syrian officers that recommended killing all journalists found between the Libyan border and Homs, and making out they had been killed in combat between terrorist groups.

He said of his departure from Homs with Colvin: "We had been advised to leave the town [of Homs] urgently, we were told 'If they find you, they will kill you.' So I left with the Sunday Times journalist [Marie Colvin], but later she wanted to go back when she saw the offensive hadn't happened."

In the deadliest period for the media since the uprising in Syria began, at least three citizen journalists have also been killed in recent days, in an apparent attempt by the regime to prevent news emerging from Homs. The three Syrians had all played prominent roles in chronicling the army's assault on Homs. One of those killed was the video blogger Rami al-Sayed, also known as Syria Pioneer, who had uploaded to the internet at least 200 videos of killing and destruction in his neighbourhood.

Colvin, a decorated foreign correspondent with more than 30 years of experience in conflict zones, and Ochlik, who last month won a World Press Photo award, died instantly when the shell struck the safe house that had been provided for them by local activists just after 9am. Colvin's body, along with Ochlik's, was recovered from the rubble just after 1pm.

Colvin's editor, John Witherow, released a statement that said: "Marie was an extraordinary figure in the life of the Sunday Times, driven by a passion to cover wars in the belief that what she did mattered. She believed profoundly that reporting could curtail the excesses of brutal regimes and make the international community take notice. Above all, as we saw in her powerful report last weekend, her thoughts were with the victims of violence.

"Throughout her long career she took risks to fulfil this goal, including being badly injured in Sri Lanka. Nothing seemed to deter her. But she was much more than a war reporter. She was a woman with a tremendous joie de vivre, full of humour and mischief and surrounded by a large circle of friends, all of whom feared the consequences of her bravery."

Colvin and Ochlik had been in Bab al-Amr for the past week reporting on the bloody siege of opposition-held parts of Syria's third city, which has claimed hundreds of lives and led to a humanitarian crisis.

The house in which the reporters were based was located next to a hospital and had been the main refuge for all reporters who had made it to Bab al-Amr in the face of a relentless barrage by regime forces.

An activist for the campaigning group Avaaz who witnessed Wednesday's attack said: "I left the house after it got struck and headed to a house across the street. The shelling continues and the bodies of the journalists are still on the ground. We can't get them out because of the intensity of the shelling even though we're only a few metres away from them."

Another witness told the Guardian that rockets were continuing to rain down on the area as the wounded tried to escape the bombed house. A graphic video posted on the internet showed the two-storey house in ruins ? a scale of damage that could only be caused by a heavy artillery round. Two bodies were visible in the rubble.

Three of the wounded are understood to be in a serious condition and in urgent need of treatment.

They face a long and perilous drive to the Lebanese border where Red Cross officials are preparing to meet them.

The foreign editor of the Times, Richard Beeston, released a short statement on Twitter that read: "Terrible news about Marie Colvin. First worked with her Beirut 85. Most courageous, glamorous foreign corr I have ever met. Tragic loss."

Colvin used a web forum to make what is believed to be her last post on Tuesday. "I think the reports of my survival may be exaggerated," she wrote. "In Baba Amr. Sickening, cannot understand how the world can stand by and I should be hardened by now. Watched a baby die today. Shrapnel, doctors could do nothing. His little tummy just heaved and heaved until he stopped. Feeling helpless. As well as cold! Will keep trying to get out the information."

On Tuesday night, Sayed also lodged a final missive. "Baba Amr is being exterminated. Do not tell me our hearts are with you because I know that. We need campaigns everywhere across the world and inside the country. People should protest in front of embassies and everywhere. Because in hours, there will be no more Baba Amr. And I expect this message to be my last."

Join us for live coverage of the latest Republican debate, hosted by CNN in Arizona
? Watch a live video stream here

9.43pm: Rick Santorum's brain is losng its grasp on language, based on his description of Iran as a "the world's most most prolific proliferator of terrorism". But after this debate, that's no surprise.

Everyone bar Ron Paul is fixating on Iran and the current president's fecklessness, which includes such statesmanlike arguments as this from Gingrich: "As long as you are America's enemy, you're safe".

9.37pm: After the "bomb Iran" section, Ron Paul is allowed to speak. "We're worried about one nuclear weapon. Think about the Cold War, the Soviet Union had 13,000 of them and we talked to them," says Paul, who wants Congress to be consulted before a declaration of war.

"We talked to the Soviets during the Cuban crisis, we could at least talk to someone who there is no proof has a nuclear weapon," says Paul. The crowd erupts in silence.

After that outbreak of common sense, Rick Santorum tells us that Syria is a puppet of Iran, showing a firm grasp of Middle East politics.

It's enough to make you want to turn to religion.

9.36pm: Foreign policy, leaving the best until last. Well, leaving something until last anyway.

In between Rick Santorum defending his strange comments about women being too emotional to serve on the frontline for the US military, the non-Ron Paul consensus is that war with Iran is basically just waiting on Israel to give the US the green light.

Hamas is going to smuggle dirty bombs over the border into the US, says Mitt Romney. He repeats his line about if he is president, Iran will not get a nuclear weapon, but it will if Barack Obama is president. If this was a limbo dancing contest, Romney could easily fit through a letter box. Only the laws of gravity are stopping him from stooping any lower.

9.35pm: Students from the Studio 20 program at NYU have been monitoring the breakdown of debate questions so far. There's been one on government (a question about debt), two of them could be classed as being about the economy and jobs, four that fell into the national security/foreign policy category, two on the candidates' conservative credentials, one on the candidates' record, two on contraception, three on immigration and one that they classed as "fluff". (Obviosuly some questions were classed in more than one category.)

In our #unasked project, no-one asked for a question on contraception; while 27% of the desired questions were about the economy and job creation.

Looks like the viewers aren't very happy about the questions, either:

9.27pm: The Guardian's Washington DC bureau chief Ewen MacAskill is back with his summary of the debate so far:

This may be the last of the debates, the end of a chain going back to South Carolina in May last year. There is one scheduled for Portland, Oregon, in March and the organisers insist it will go ahead, though doubts remain.

This one has been much better in some ways than the early ones, which had too many candidates. The downside is that the remaining candidates know each other too well now, and are arguing about extremely detailed and ambiguous points. There is also a lot of dissembling. Romney manages to present himself as both opposed to earmarks and in favour, in favour of bail-outs and opposed to them. It has reached the point of ridiculous when Romney can accuse Santorum of being the originator of his healthcare reform in Massachusetts. Santorum is just as guilty in dissembling, especially over the earmarks. So what do we end up with? A very muddy and near incomprehensible debate.

Twitter appears to agree with Ewen's description.

9.23pm: And we are back with the compulsory stupid question: "sum yourself up in one word". Really.

Ron Paul: Consistent

Rick Santorum: Courage

Mitt Romney: Resolute

Newt Gingrich: Cocaine. No, no - Cheerful.

Now, none of those was the word I would have used.

9.16pm: Finally, Mitt Romney has been exposed for the fraud he is: a thousand 40-something journalists have fact-checked his abuse of a quote from Seinfeld, forgetting that no one cares.

9.15pm: It's an ad break, and John King warns or threatens us that the candidates will be asked "to define themselves in one word, and one word only".

I could do that: one word for all four of them.

9.13pm: Finally: immigration. And John King manages to refer to "illegals", nice touch.

Basically, the candidates think that any employers who hires an illegal immigrant should also be deported. Or put to work building the fence along the border.

9.09pm: Here's a flavour of the current debate, from Rick Santorum aimed at Romney:

Michael Dukakis balanced his budget for 10 years. Did that help him become president of the United States?

It would take to long to explain why, but in summary: zing.

Now Romney and Santorum are shouting over each other, with the audience joining in.

There are two things here. One is ? like the joke about wrestling with a pig (you get dirty and the pig likes it), Mitt Romney is rolling in the mud here with Santorum. That probably doesn't help either of them, but it certainly doesn't help Mr Presidential Inevitability, Mitt Romney.

Number two is: if anything helps along the tentative calls for a new GOP candidate and rejecting all of the candidates on stage tonight, then this debate is doing a fine job.

Even Republican voters are fed up of it:

9.04pm: So far this debate is like watching three drunks trying to start a fight and falling over.

Larry Sabato appears to agree (more politely).

9.01pm: I'm sure this long and disturbing discussion on the evils of birth control ? a gateway drug to abortion, according to Ron Paul, and I'm not kidding ? will do wonders for boosting the Republican party's share of the women's vote.

I've lost track of what exactly is at issue here, I think it's a discussion about how many angels can dance on a morning-after pill.

8.54pm: To further curry favour, moderator John King basically tells the candidates to just go nuts and attack the government. This leads to Rick Santorum explaining himself thus: "Just because I'm talking about it doesn't mean I want a government programme to fix it."

Anyway, the next several minutes are devoted to bashing Obama.

8.51pm: We're back after the ad break with a question about birth control ? and a huge negative response from the audience. "Look we're not going to spend a lot of time on this," John King is forced to tell the unruly mob that is waving pitchforks.

Newt Gingrich quickly seizes control of the debate and turns the question around to make it about the government.

Yes, infanticide. Apparently Barack Obama is all in favour of it. Why has the liberal media kept this quiet?

8.46pm: The Guardian's Ewen MacAskill is at the debate venue in Arizona and sends his view:

Romney looks strained compared with the start of the campaign, or even in Iowa at the start of January. His wrinkles are more prominent, his eyes tired. Maybe his campaign is in trouble? Maybe he is worried about losing Michigan next week?

Romney has opted to battle in this debate on the economy, the main issue of importance to voters. It would be hard for Romney, as a Mormon, to tackle Santorom over his remarks about Satanism but probably will not be too unhappy if King or someone in the audience raises it.

Santorum much more relaxed than Romney. He dealt pretty well with his weak spot, his record of voting for earmarks. He pointed out that Romney had come looking for an earmark to help save the Salt Lake Olympics. Romney replied that yes he had but Santorum had also voted for the infamous Bridge for Nowhere. I am not sure what Romney's logic is: it is okay if he is asking for an earmark but wrong when an Alaskan senator does it?

Yes I thought Mitt looks like he has a few more gray hairs tonight.

8.43pm: Now the candidates have to explain why none of them wanted to bail out the auto industry, an important topic in Michigan, which votes in its primary next week.

First off, Santorum accuses Romney of a double standard of not helping Detroit but happy to bail out the banks of Wall Street.

"Nice try but now let's look at the facts," sneers Romney, who promptly tells fibs about his position on restructuring the auto industry.

John King asks him a serious question about how there were no banks around to manage the bankruptcy of the auto industries, but Romney entirely ignores the question and blames the unions.

Santorum smacks Romney for comparing bailing out the airlines after 9/11 and the Wall Street bail out.

8.35pm: I'm not sure anyone came out of that last skirmish on earmarks very well. Somewhere it turned into a circular firing squad, with the members of the firing squad also blindfolded. In conclusion: it ended.

8.36pm: Rick Santorum is now defending earmarks, the wacky American system whereby individual congresspersons can add sending to bills. Romney has been hitting Santorum on the matter, but Santo is giving it back, pointing out that Romney asked for earmarks as head of the Winter Olympics and as governor of Massachusetts.

"I didn't follow all of that," says Romney. Now that's just rude Mitt. Once again he comes across as a nasty piece of work. "While I was fighting to save the Olympics, you were fighting to save the Bridge to Nowhere," says Mitt, namechecking that bridge in Alaska.

Romney has got himself into a tangle here, as Santorum is running all over him on the minutae of earmarks. Mitt even got some boos there.

This has run into the sand but Romney is now under fire from Gingrich and Santorum, with Gingrich getting off a zinger at Mitt, pointing out that when he asked for earmarks it was right but wrong for everyone else.

8.28pm: Newt Gingrich is going on and on about his energy plan to do everything, including revolutionising government somehow. Because that worked so well for Rick Perry if I recall.

8.25pm: John King asks Mitt Romney to explain his silly "severely conservative" governor line from a recent speech. "I was without question a conservative governor of our state," says Romney, noting that he balanced the budget in Massachusetts four times ? as required by law.

Oh and here's the "you have to be a fiscal conservative in business" line again. On that basis Google would have gone out of business in year one, so that's just nonsense. Many businesses, especially start-ups, don't "balance" their budgets, sometimes for years.

8.22pm: Rick Santorum shows his ability as a debater in his response to the "fake" line from Ron Paul. He stays calm, reeling off the various conservative spending plaudits he has won, and manages to smack Ron Paul at the same time. Gingrich would have probably exploded.

"That's always he problem when you compare yourself to the other members of Congress," says Ron Paul, who is now defending himself.

8.20pm: Sigh. Once again Newt Gingrich claims to have balanced the budget while he was speaker for four years, which is simply false. It was twice and that was on the back of tax increases and a bubbling economy.

John King asks Ron Paul: "You have a new television ad that labels [Santorum] a fake. Why?" Ron Paul replies: "Because he's a fake."

Santorum is stitting there with a wry grin on his face.

8.15pm: Now the first question: and it's on the national debt. Rick Santorum is first up, and his concrete proposal is to repeal Obamacare. And all that defence spending? "You need to go to remedial math class," says Rick.

Asked to respond, Mitt Romney goes straight at Rick Santorum, slamming his record before saying what he really wants to do is answer the question. Apparently among Santorum's sins included voting for something called Davis-Bacon, which may or may not be a type of sandwich.

Santorum gives it back to Romney, talking about taxes he raised in Massachusetts and also accusing Mitt of wanting to raise taxes on the wealthy in his latest proposals today.

"There were so many misrepresentations in there it's going to take me a while," says Romney, his standard reply to debate criticism.

8.09pm: In tonight's debate, the candidates get to sit down, which probably helps Rick Santorum.

A brief flub there. "I'm here to talk about positive solutions for this country that includes everybody from the bottom up," says Rick. Yes, he said "bottom up". Snigger all you like, sniggerers.

8.06pm: Now the four men are on stage. We've had the Pledge of Allegiance already, John King tells us, so it's on to the national anthem. In an unusual choice, CNN hve gone with the American national anthem tonight. Apparently that star spangled banner does yet wave, according to sources.

8.02pm: And here's CNN's John King with the now standard Deep Voiced Intro, like one of those movie trailers for a horror movie. Which is it, sort of. It pobably feels like a zombie flick to Mitt Romney.

7.58pm: Tonight's debate summarised in graphic form: it's Man on Dog versus Dog on Roof (thanks to Melissa McEwan at Shakesville for this work of genius).

"Man on Dog" is of course the social conservative Rick Santorum, who once famously compared gay marriage to bestiality. "Dog on Roof" is the managerial genius of Mitt Romney, who will strap the American economy to the roof of his car in the interests of efficiency, even if it makes it sick.

And that's it, really. What a marvellous choice for GOP voters, eh?

7.45pm: For some real insight into the Republican debates ? as opposed to this rubbish ? and the questions that have been asked, then it is worth reading about our #unasked project.

This is a piece of compelling analysis about what topics have been covered exhaustively, and what questions have been brushed by in passing.

The Guardian and NYU's Studio 20 studied all the questions journalists have asked during the 20 Republican debates held so far. The results reveal the obsessions of the campaign press, and what they think the presidential election is about. In this interactive feature you can tell us which of the news media's priorities is also a priority for you.

This great visualisation shows some of the questions that haven't been asked. Just two on climate change, for example.

And this interactive compares the media agenda with the priorities of voters.

After 20 or so debates, depending on how you count them, you'd think every topic under the sun has been covered? As it happens: no. Here's our study of the debate questions to date.

It's all part of our Citizens Agenda project, a collaboration with the students of the Studio 20 program at New York University.

7.39pm: Say what you like about Rick Santorum ? and we will, given the chance later tonight ? but he's not giving up on the scary God-talk. Just today he was telling the people of Arizona about the White House's "war on Christianity":

We're seeing very evidently what the president's moral codes and principles are about. We see a president who is systematically trying to crush the traditional Judeo-Christian values of America. We saw it with Obamacare and the implementation of Obamacare, where his values are going to be imposed on a church's values.

Yes, that's just the sort of apocalyptic talk goes down so well with independent voters in a general election.

7.00pm: Welcome to live coverage of the 20th and perhaps final debate between the GOP presidential candidates, this time in sunny Arizona.

In five days time the Republican voters of Michigan and Arizona will make their choice, and a week later comes Super Tuesday: less super than previous election cycles, but one that will decide if this contest is to end abruptly, with Mitt Romney as the Republican nominee, or if it is to drag on, as some fear it might, right up to the GOP convention in Tampa in August.

Tonight is the first real debate for almost month, offering perhaps one last bonfire of the vanities that has so far consumed Michele Bachmann, Rick Perry, Tim Pawlenty, Jon Huntsman and of course Herman Cain.

For those of you who have followed the last 19 debates: we're thinking about striking a veterans medal. "For those who served in the 2012 GOP debates," or similar. For those of you for whom this is the first time: welcome, and be afraid. Very afraid.

All four of the candidates on stage are familiar, but let's run through what each one wants to get out of tonight.

Mitt Romney: Still the inevitable nominee and frontrunner, despite all that has been flung at him. Like Gulliver he has perhaps been worn down by the midgets he has faced, and tied up in knots but he needs another good performance tonight, as he did in the last two debates in South Carolina abut a million years ago. Today he released some detailed tax cut proposals and he'll be making the most of them here, to win over the wavering and put Newt Gingrich and Rick Santorum behind him.

Rick Santorum: As he has risen in he polls, and taken some eye-catching victories in Minnesota and Colorado, the focus has found some of his more extraordinary positions in the past. Santorum is a good debater and has had some good performances so far ? but tonight will be the first time he will clearly be occupying the number one challenger spot as the Anti-Romney. Will he stick to bashing Barack Obama, or will he needle Romney? On a good day he could cause Romney a lot of pain, being more fluent than the former Massachusetts governor, if that's the route he goes down ? and avoids getting bogged down in discussions about theology or Satan's attack on America.

Newt Gingrich: The previous Anti-Romney, he has slid disasterously in the polls and is now out of contention. But he is also a better debater than Romney. His choice is whether he takes bipartisan potshots at Santorum and Romney equally, or whether he concentrates his fire on Romney alone. As always with Newt, though, he can be his own worst enemy: too much Professor Gingrich wibbling on about moon bases or "lean six sigma," whatever that is, and he loses. But he needs a big win tonight to remain a serious contender.

Ron Paul: The insurgent libertarian-leaning candidate has been a disappointment in the voting so far, for all his fervent base, money and organisation. He also seems to lean towards Mitt Romney ? the two appear to be quite friendly ? and Paul may muddy the water by attacking Santorum as a faux-conservative. He remains a rogue element, to be treated warily by the other three, who wnt to flatter his supporters while smacking down his more unorthodox ideas.

We will be following the debate from gavel to gavel (if they had gavels) right here, with contributions from our correspondents in the field and the redoubtable Ana Marie Cox, as well as the best of the Twitterverse.

And you can add to this: by leaving your comments below.

A statement on the website of the Pacific Institute, which Gleick founded and now heads, said the board was "deeply concerned" about the ruse carried out against Heartland.

"Neither the board nor the staff of the Pacific Institute knew of, played any role in, or condones these events," the board said.

Gleick was not the only potential career casualty of the Heartland affair. Earlier on Wednesday, a Democratic member of Congress called for an investigation into whether a Department of the Interior employee, Indur Goklany, had broken the rules by taking a salary from Heartland at the same time he was working for the federal government. The payments were revealed in Heartland documents released by Gleick.

The statement from the Pacific Institute comes just 24 hours after the board reaffirmed its support for Gleick. "Dr Gleick has been and continues to be an integral part of our team," the earlier statement said.

But since then a number of its funders have expressed displeasure at Gleick's deception, the Guardian has learned.

"Obviously we are concerned about any allegations of unethical conduct and Dr Gleick has already admitted to it and apologised. We are disappointed in his poor judgment," said Marc Moorghen, communications manager for the Conrad N Hilton Foundation. The foundation was among larger donors to the Pacific Institute in 2010, contributing $130,000, according to the institute's tax filings, which are posted on its website.

Moorghen said the funds were for water in developing countries and did not involve climate change.

Gleick's admission on Monday night that he had tricked Heartland into sending him the documents has set off a ferocious debate in the community of scientists and advocates who work on climate change.

He was hailed as a hero by Naomi Klein and by science educator Scott Mandia, who told the Guardian that Gleick had acted as any journalist would. "Peter Gleick, a scientist who is also a journalist, just used the same tricks that any investigative reporter uses to uncover the truth. He is the hero and Heartland remains the villain. He will have many people lining up to support him."

But Gleick has faced increasing criticism since then from fellow scientists, who contend that his techniques were a betrayal of the rigorous method and transparency that are at the heart of science.

Gavin Schmidt, the Nasa climate modeller who founded the RealClimate blog, was scathing in a comment first reported in the New York Times.

"Gleick's actions were completely irresponsible, and while the information uncovered was interesting (if unsurprising), it in no way justified his actions. There is an integrity required to do science (and talk about it credibly), and he has unfortunately failed this test."

The furore now looks set to eclipse what had until now been an admirable career for Gleick. He was forced to step down as chairman of the American Geophysical Union's taskforce on scientific ethics. On Tuesday, the San Francisco Chronicle dropped him as a columnist.

It also overwhelmed the debate about Heartland's disinformation campaign ? which included plans to distort science teaching for school children.

However, Greenpeace and other campaigning groups were working hard on Wednesday to expose a number of individuals who were revealed in the documents to be on Heartland's payroll, and were planning to put pressure on the publicly-funded institutions that were the main employers.

In one such instance on Wednesday, Raúl Grijalva, a Democratic member of Congress, called for a congressional investigation into whether Goklany, described as a senior policy analyst at the Department of the Interior, had broken rules by accepting a monthly stipend of $1,000 from Heartland.

Grijalva's letter mirrored arguments raised in a letter to the interior secretary, Ken Salazar, from Greenpeace.

The Heartland fundraising documents indicate that Goklany was taken on to write a chapter for the thinktank's annual climate report, which works to try to undermine the UN's climate science organisation, the IPCC.

Greenpeace has written similar letters of protest to six universities including Harvard, the University of Missouri, Michigan Technical University and Arizona State University in the US, and the University of Victoria and Lakehead University in Canada about scientists revealed to have received funds from Heartland to work on its big anti-IPCC effort.

Greenpeace argued that the funds violated conflict of interest regulations for government-funded research projects.

This blog has ended. Coverage continues here

Live coverage as Mitt Romney unveils plans for 20% tax cuts while the Obama administration offers lower corporate taxes

10.30am: The Republican presidential contenders gather in Arizona, ahead of tonight's big event, the debate hosted by CNN. But will Rick Santorum get any questions about Satan's takeover of America?

Meanwhile, the Obama administration unveils the offer of a cut in the corporate tax rate, puncturing a Republican talking point about US corporate tax rates being among the highest in the world.

The Guardian's Ryan Devereaux has a summary of the latest events on the campaign trail, with just six days to go until voting in the Arizona and Michigan primaries:

? The Republican presidential candidates debate tonight in Mesa, Arizona. It's been nearly a month since the candidates last faced off and all eyes will be on Mitt Romney and Rick Santorum. With key contests looming in Arizona and Michigan, tonight's debate is crucial for Santorum, who has been rising in state and national polls since his hat-trick of wins in Colorado, Minnesota and Missouri. Romney, meanwhile, will seek to cast Santorum as a Washington insider.

? With Arizona's primary next Tuesday, a poll from CNN, Time and ORC International has Santorum and Romney in a tight race, with one third of respondents saying they could still change their minds. According to the poll, Romney is supported by 36% of the voters, while Santorum has 32%.

? Rick Santorum has sidestepped a past claim that the US is under attack from Satan. Yesterday the Drudge Report ran a headline at the top of its page reading, "Satan has his sights on the United States of America." The headline was a reference to a speech Santorum made four years ago. On Tuesday Santorum was asked if the Prince of Darkness was still laying siege to the US. He said: "These are questions that are not relevant to what's being discussed in America today."

? In Michigan, the Detroit News endorsed Mitt Romney but not without an important qualification: "We disagree with Romney on a point vital to Michigan ? his opposition to the bailout of the domestic automobile industry." The endorsement goes on to say, however, that the issue "isn't a differentiator in the GOP primary."

? Finally, in what was obviously the biggest political news of the day, someone has made a portrait of Rick Santorum entirely composed of a mosaic of gay porn. The very much Not Safe For Work image can be viewed here.

10.50am: Only Rick Santorum and Mitt Romey are out and about campaigning in Arizona today, indicating that Ron Paul and Newt Gingrich have given up on the state.

Rick Santorum ? 11.30am MT: Addresses a Tucson Tea Party rally.

Mitt Romney ? 9.50am MT: Holds a rally at the Tri-City Christian Academy gym, Chandler.

The Guardian's Ewen MacAskill is at the Romney event this morning and he emails to say: "Something you do not see often at Romney events: a queue."

11.06am: More from the Detroit News endorsement of one-time Michigan native Mitt Romney, based in part on the idea that he alone of the Republican field can defeat Obama in November:

Very conservative Republicans have been lukewarm to Romney because of his history of more moderate positions on social issues. They have flirted with each of his rivals looking for a true standard bearer of conservative values. One by one, Herman Cain, Michele Bachmann, Rick Perry, Ron Paul, Newt Gingrich and Rick Santorum have enjoyed a burst of popularity at Romney's expense.

Santorum, Gingrich and Paul are challenging Romney on the Michigan ballot next Tuesday. But those Republicans are delusional if they think either Santorum or Gingrich can prevail in the fall against Obama.

Naturally, Republican grassroots really appreciate being called "delusional" by the media.

11.40am: A new brace of polls via NBC News and Marist finds Mitt Romney comfortably in the lead in Arizona but locked in a bitter struggle with Rick Santorum in Michigan:

In Michigan ? which has turned into a make-or-break contest for Romney ? the former Massachusetts governor gets the support of 37% of likely GOP primary voters, including those who are leaning toward a particular candidate.

Santorum, the former Pennsylvania senator, gets 35%, and he's followed by Texas Rep. Ron Paul at 13% and former House Speaker Newt Gingrich at 8%.

The happier scene in Arizona sees Romney on 43%, Santorum with 27%, Gingrich on 16% and Paul 11%. And here's the reason why: Romney's huge lead among early voters, thanks to Romney's organisational clout:

And among those who have voted early or absentee in Arizona ? more than half of all likely Republicans voters in the poll ? Romney holds a 30-point advantage over Santorum, 52% to 22%.

12pm: The Guardian's Ewen MacAskill says the queue of people waiting outside the Mitt Romney campaign event in Arizona this morning wasn't quite as noteworthy as it first seemed:

I was quite impressed at first: it is unusual at a Romney event. He is not a big draw. But once inside, the gymnasium where the rally is being held is far from full. The Romney team had been expecting more. Police were talking about an overflow room and how it was no longer going to be needed. So even in Arizona, Romney's lack of charisma and excitement strikes again.

12.12pm: Republicans love to crow that America's corporate tax rate of 35% is among the highest in the industrialised world ? although a plethora of tax breaks and legal loopholes suggest otherwise.

Today, however, the Obama administration is going to use a Treasury department briefing by Tim Geithner to roll out cuts in the corporate tax rate combined with loophole closures, as AP reports:

The Obama administration is planning to propose cutting the top tax rate for corporations to 28%, and pay for it by eliminating dozens of tax loopholes companies now use to lower their rates, a senior administration official said.

Chances of a deeply divided Congress revamping a tax system regarded as convoluted across the political spectrum seems remote in an election year, but the announcement on Wednesday is certain to fuel debate in the run-up to November's elections.

12.23pm: Amid all the talk of a contested convention for the Republicans in Tampa, veteran Democratic pollster Stan Greenberg tells the Guardian that the GOP nominee may not be one of the current contenders.

According to Greenberg, leading conservative players may "select a candidate" after the Super Tuesday primaries if a clear front runner fails to emerge.

There is a lot of discussion of this prospect around the conservative blogosphere but to be honest, contested conventions in modern politics are a lot like unicorns: people might want one but it never makes an appearance in reality.

12.35pm: The Treasury and the White House have now released a joint report on the president's plan for business tax reform:

The United States now essentially trades off greater tax expenditures, loopholes, and tax planning for a higher statutory corporate tax rate relative to other countries. This is a poor trade that produces a tax system that is uncompetitive relative to other countries, distorts business decision making, and slows economic growth.

The full document is available in pdf format here.

The New York Times reports that balancing the existing tax breaks with the proposed lower rate could be difficult if the change to the corporate tax code isn't to add to the deficit, as the White House claims will be the case:

Nonpartisan tax analysts consistently find that corporations here on average pay just slightly more than their competitors in other developed countries after exploiting the many tax breaks and loopholes. Recent news accounts have highlighted the low effective rates paid by companies like Google, Boeing and General Electric.

12.46pm: Buddy Roemer has announced this morning that he is withdrawing from the GOP nomination process. If you thought, "Buddy who?" then you've correctly identified the problem. Apparently it's all the media's fault that the former governor of Louisiana failed to take off.

Roemer says he's going to run for the Reform party nomination. And if you thought, "Reform what?" then [repeat].

12.52pm: President Obama attended a ground-breaking ceremony for the Smithsonian's new National Museum of African American History and Culture on the National Mall this morning, saying:

It was on this ground long ago that lives were once traded, where hundreds of thousands once marched for jobs and for freedom. It was here that the pillars of democracy were built often by black hands.

The museum itself will be built to sit on the Mall between the Washington Monument and the National Museum of American History, and is expected to be completed by 2015. Half the estimated $500m cost has been approved by Congress, with the rest coming from corporate and personal donations.

1.10pm: You wait for weeks for detailed tax reform proposals and then two come along at once.

So far today we've had the White House outline its attempts at corporate tax reform. Now the Romney campaign ? perhaps in response ? has pushed out more details of his new larger-scale tax reforms. The Wall Street Journal distils the details:

Mr Romney wants to cut individual tax rates by 20% in all six brackets, reducing the tax the wealthiest Americans pay to 28% from 35%. That target is slightly higher than the 25% rate Mr Romney laid out earlier in the campaign.

The tax rate for people in the lowest income bracket would drop to 8% from 10%, and would fall to 20% from 25% for those Americans in the middle.

Mr Romney would maintain the current 15% tax rate on capital gains and dividends for households that earn $200,000 a year or more. Those earning less than that amount would pay no taxes on capital gains and dividends under his plan.

How to pay for all this, especially the across the board tax cuts? "Mr Romney offered no specific proposals to increase revenue through the tax code," reports the WSJ, "Instead, he would leave those decisions to Congress." Always a recipe for success.

1.22pm: Mitt Romney was to have made a big speech on the economy on Friday, and was presumably planning to unroll this tax cut plan then. But possibly to take advantage of tonight's debate, create a clear contrast with Rick Santorum and overcome a polling wobble in Michigan, Romney has pushed the button today.

The Romney campaign has put up more detail but still not much detail on how to pay for some fairly stiff tax cuts. This is what we get from Romney's website:

Stronger economic growth and reductions in spending will help to ensure that these tax cuts do not expand deficits. In addition, higher-income Americans in particular will see limits placed on deductions, exemptions, and credits that are currently available. The result will be a pro-growth tax code that still raises the necessary revenue, retains the existing progressivity, and ensures that middle-income Americans see real tax relief.

The bit in bold is very, very interesting: Mitt Romney looking past the GOP primaries and tackling his 1% problem? (Meanwhile, Newt Gingrich is sharpening a stick.)

The New York Times talks to Glenn Hubbard, Romney's economic advisor, about the fiscal implications:

Mr Hubbard said three different revenue streams would keep the plan from increasing the budget deficit: the "dynamic" effects of economic growth, the additional income that would be subject to taxation through "base broadening," and spending cuts Mr Romney plans that would reach $500 billion per year by 2016. The campaign promised more specifics on those spending cuts within the next week.

"Base broadening" here means bringing in additional tax payers or taxable income. At least he didn't also suggest "eliminating waste and inefficiency," the other usual suspect for filling fiscal holes.

1.40pm: Politico's Jake Sherman has a scoop on Mitt Romney's athletic attire:

So Lululemon has now jumped the shark. Or downward-dogged the shark, to be accurate. Sherman also mentions that he got into the hotel gym before Romney at 5.30am. Obviously Romney slept in. Slacker.

2pm: So while Mitt Romney is churning out Serious Proposals, his main rival for the moment, Rick Santorum, is having to discuss Satan's war on America.

Last night, though, Santorum told a rally in Phoenix that the American people want "the opportunity to see what's in here, and what's up here, and what's burning down here," ? although what Santorum meant by "what's burning down here" was deliciously ambiguous, given his hand gestures. His loins? Piles? Pants on fire? Who can say, other than Mrs Santorum and his personal physician.

2.15pm: For further analysis of Mitt Romney's new tax cuts, the Washington Post's Greg Sargent talks to Bob McIntyre, president of Citizens for Tax Justice, who describes the outcome as a huge tax cut for the rich and a total tax cut of $10tn over 10 years:

So how does this all square with Romney's claim [that he would "make sure the top one percent keeps paying the current share they're paying or more"] about the one percent? McIntyre says the key is that Romney said the one percent's "share" would not drop. He didn't say the amount the one percent pays wouldn't drop.

"If you reduce the whole thing by 20% then they can go down by 20% and still pay the same share," McIntyre explains.

2.41pm: Buzzfeed has dug out audio from a 2008 interview Rick Santorum conducted with radio show host Mike Signorile. In the interview Santorum insists that child abuse is higher in same sex relationships as part of his argument about why gay people should not be allowed to get married. The former Pennsylvania senator doesn't have any evidence to back up his claim, but hey, never mind.

"As of course you know, as you course you know, that abuse in gay relationships is higher than in heterosexual relationships, it's absolutely clear about that. Sexual abuse, violence to children, is higher in those relationships. It's fact."

Santorum is also brilliantly vehement when Signorile describes Santorum's longstanding argument that "if same sex marriage is ok, then so is polygamy" as specious.

No it's not different it's the same. No it's not a specious argument.

Ps ? This is Adam Gabbatt taking over from Richard for a few hours.

2.57pm: Barack Obama is tied with Mitt Romney in Arizona, according to our friends at Public Policy Polling.

Obama and Romney each stand at 47% in PPP's latest poll, while the president leads both Ron Paul and Newt Gingrich by 4 points.

"The only Republican he actually runs behind is Rick Santorum, although only by a single point at 47-46," PPP's press release says.

"This is the latest in an increasingly long line of our polls recently that challenge the premise that Romney is a much stronger general election candidate than Santorum."

John McCain won in Arizona in 2008, with 53.8% of the vote to Obama's 45%.

Good news for Obama ? although PPP do qualify the poll by saying it is unlikely the President would be able to beat Romney in Arizona once the GOP unifies around one candidate.

"But the fact that we're even talking about Arizona as potentially being on the board right now is a big a shift from where we were a couple months ago."

Tom Jensen from PPP:

Arizona is a great microcosm of how Barack Obama's reelection prospects have improved over the last 3 months. When we polled there in November his approval numbers were atrocious and his prospects for winning the state in the general election didn't look very good. Now he's getting more popular, the Republicans are getting less popular, and he appears to have a decent chance there.

3.22pm: Meanwhile, in Virginia:

.@Vahousedems finding many flaws in @bobmcdonnell suggested amendments to #sb484 #transvaginal #ultrasound bill

? VA House Democrats (@VAHouseDems) February 22, 2012

Surely there has to be a question on transvaginal ultrasounds in tonight's debate?

3.31pm: Below the line Mitt Romney's tax plan isn't winning many plaudits:

gwpriester

Cool plan Mitt. I guess with the reduced amount of tax revenue we can slash all other spending to the bone. And we don't need to worry about the deficit getting larger, we'll just put the expenses on the credit card like George W. did and leave it for the next Democrat to deal with.

Give me a break!!!

3.57pm: Bob McDonnell, Virginia governor, has given in to pressure and recommended amendments to the SB484 bill that would have required women to undergo transvaginal ultrasound scans before being granted abortions.

"I believe there is no need to direct by statute that further invasive ultrasound procedures be done," McDonnell said in a statement. "Mandating an invasive procedure in order to give informed consent is not a proper role for the state."

Alec MacGillis, writing in the New Republic, says it's not surprising, as McDonnell is harbouring VP ambitions:

And just like that, Virginia's vaginal-probe ultrasound goes up in the smoke of burning vice presidential ambitions. is.gd/5Z7Jub

? Alec MacGillis (@AlecMacGillis) February 22, 2012

4.19pm: More from Bob McDonnell's statement after he recommended amendments which would not force women in Virginia to undergo transvaginal ultrasounds before having an abortion.

Over the past days I have discussed the specific language of the proposed legislation with other governors, physicians, attorneys, legislators, advocacy groups, and citizens. It is apparent that several amendments to the proposed legislation are needed to address various medical and legal issues which have arisen. It is clear that in the majority of cases, a routine external, transabdominal ultrasound is sufficient to meet the bill's stated purpose, that is, to determine gestational age. I have come to understand that the medical practice and standard of care currently guide physicians to use other procedures to find the gestational age of the child, when abdominal ultrasounds cannot do so. Determining gestational age is essential for legal reasons, to know the trimester of the pregnancy in order to comply with the law, and for medical reasons as well.

Thus, having looked at the current proposal, I believe there is no need to direct by statute that further invasive ultrasound procedures be done. Mandating an invasive procedure in order to give informed consent is not a proper role for the state. No person should be directed to undergo an invasive procedure by the state, without their consent, as a precondition to another medical procedure.

For this reason, I have recommended to the General Assembly a series of amendments to this bill. I am requesting that the General Assembly amend this bill to explicitly state that no woman in Virginia will have to undergo a transvaginal ultrasound involuntarily. I am asking the General Assembly to state in this legislation that only a transabdominal, or external, ultrasound will be required to satisfy the requirements to determine gestational age. Should a doctor determine that another form of ultrasound may be necessary to provide the necessary images and information that will be an issue for the doctor and the patient. The government will have no role in that medical decision.

4.34pm: Mitt Romney's tax plan "has the appeal of simplicity" and could help him win over not only conservative voters but independents at a general election, writes Ewen MacAskill.

The prospect of tax cuts, particularly the idea of 20%, is a tantalising prospect as voters do their sums, regardless of how much progressives argue that tax cuts mean poorer services.

The plan is aimed at giving Romney a much-needed edge in a closely-fought campaign. Michigan is his home state and defeat at the hands of Santorum would raise serious doubts about his chances of becoming the Republican presidential nominee.

Voters in Michigan, Arizona and Super Tuesday states such as Ohio rate the economy and unemployment are the most important issues.

Romney, speaking in Chandler, argued tax cuts would help the economy grow. He suggested 20% cuts in each of six tax brackets: 10%, 15%, 25%, 28%, 33% and 35%. These would become 8%, 12%, 20%, 22.4%, 26.4% and 28%.

The former Massachusetts governor said his plan would be revenue neutral, by limiting deductions, particularly for the wealthiest. Among deductions he planned to limit are charitable contributions and relief on mortgage interest payments.

4.56pm: Slate's William Saletan has taken an indepth look at when, and how, Mitt Romney changed position on abortion ? from pro-choice to his current pro-life position.

When you see the story in its full context, three things become clear. First, this was no flip-flop. Romney is a man with many facets, groping his way through a series of fluid positions on an array of difficult issues. His journey isn't complete. It never will be. Second, for Romney, abortion was never really a policy question. He didn't want to change the law. What he wanted to change was his identity. And third, the malleability at Romney's core is as much about his past as about his future. Again and again, he has struggled to make sense not just of what he should do, but of who he has been. The problem with Romney isn't that he keeps changing his mind. The problem is that he keeps changing his story.

Slate also has a pretty impressive timeline on Romney's development.

5.17pm: Reuters has just posted a newsflash on Twitter suggesting that Comedy Central stars Jon Stewart and Stephen Colbert have been sent letters that threaten senators. There are no more details yet.

FLASH: US law enforcement officials probing letters sent to TV personalities Jon Stewart, Stephen Colbert that threaten attacks on senators.

? Reuters Top News (@Reuters) February 22, 2012

5.31pm: New Mexico governor Susana Martinez has lost her hair stylist due to her opposition to gay marriage, according to kob.com.

Antonio Darden, a popular stylist who runs Antonio's Hair Studio in Santa Fe, said he cut Martinez' hair three times, but that's it - unless she changes her mind about gay marriage.

"The governor's aides called not too long ago, wanting another appointment to come in," Darden said. "Because of her stances and her views on this I told her aides no. They called the next day, asking if I'd changed my mind about taking the governor in and I said no again."

The governor has said she believes marriage should be between a man and a woman, and that does not cut it with Darden.

"I think it's just equality, dignity for everyone," the popular hair stylist said. "I think everybody should be allowed the right to be together. My partner and I have been together for 15 years."

Could there be a wave of politicians and their associates being refused services due to controversial stances? How would Callista Gingrich cope without her hairdresser?

5.46pm: More from Reuters on the letters sent to Stephen Colbert and John Stewart. The letters threatened biological attacks on US senators, according to the report, and three members of Congress have received mail containing a suspicious powder, which was later found to be harmless. Law enforcement officials warned on Wednesday evening that more may be coming:

Other letters to a number of news organizations and postmarked Oregon warned that 100 letters had been sent to the Washington or home-state offices of U.S. senators and that 10 of those contained a deadly pathogen, a law enforcement source said.

At least two of the letters already received - one to the home-state office of a senator and the other to the district office of a member of the House of Representatives - contained a powdery substance.

Tests found the substance to be harmless, according to a statement by Senate Sergeant at Arms Terrance Gainer, the chamber's chief law enforcement officer.

6.14pm: Mitt Romney's tenure as a Marriott board member ? which included a six year spell as chair of its audit committee saw the company "repeatedly utilize complex tax-avoidance manoeuvres, prompting at least two tangles with the Internal Revenue Service", according to a Bloomberg report.

A federal appeals court invalidated the maneuver in a 2009 ruling, siding with the U.S. Department of Justice, which called Marriott's transaction and attempted tax benefits "fictitious," "artificial," "spectral," an "illusion" and a "scheme." Marriott had argued the plan predated government efforts to close such shelters.

Employing another strategy, Marriott legally avoided hundreds of millions of dollars in income taxes thanks to a federal tax-credit program criticized and allowed to expire by Congress. Marriott has also shifted profits to a Luxembourg shell company. During Romney's years on the board, Marriott's effective tax rate dipped as low as 6.8 percent, compared with the federal corporate statutory rate of 35 percent.

The Marriott chain was founded by a Mormon, of course, and you can find the Book of Mormon alongside the bible in Marriott hotel rooms. Bloomberg point out that Willard Mitt Romney was actually named after the chain's founder ? J. Willard Marriott, who was a friend of Mitt's father.

6.30pm: Arizona fingerwaggler and governor Jan Brewer and her tourism officials have splashed out $300,000 on advertising over the next couple of weeks, according to azcentral.com.

"The ad, which features Brewer in a white suit against the backdrop of the Arizona desert, will air 44 times on CNN this week and next week ? the week of Arizona and Michigan's primary," the report said.

How successful featuring Brewer in the ad will be remains to be seen.

7.15pm: That's it for today ? join Richard Adams here for our live blog of tonight's CNN Republican debate in Arizona.

1. Tim Pawlenty's unwillingness to attack Mitt Romney. A former governor of Minnesota, Pawlenty was going to be Mitt Romney's chief nemesis in the 2012 nomination race. He had a relatively conservative record in office and could appeal to the same grassroots conservatives whom Rick Santorum has seemed to capture.

In a 13 June 2011 debate, Pawlenty was unwilling to criticize Romney for his Massachusetts healthcare plan, after having done so in interviews before the debate. His debate performance was panned, and he was out of the race two months later. Did the debate really cost him?

Pawlenty's candidacy never caught fire ? before or after the debate. He was at 7% in a late May Iowa poll, and he was at 6% in a poll taken in the days following debate. Perhaps, if Pawlenty had taken the fight ? Gingrich-style ?
to Romney, he would have risen in the polls. We can't know the answer to that, but it's not as if Pawlenty blew a large lead with his subpar debate execution.

2. "Oops" and other Rick Perry classics. The entrance of Rick Perry into the presidential race came with a great boom. He launched into the lead in the national and many state polls. Perry was a governor with a conservative record, establishment backing, and strong support from the conservative blogosphere. Then came the debates. 

Perry's most renowned blunder may have been "oops" in November's debate in Michigan, but it was, in fact, two debates in September that started the Perry slide. After topping out at around 32% in the national polls on the 13 September, just after the 12 September debate, Perry's ranking dropped. The fall was slow at first, but, after Mitt Romney crushed him in a 22 September debate, the decline accelerated. In polls taken the week following that debate, Perry experienced a 10-point drop in just seven days. By the time it was over, Perry stood at just 15% in the polls. A more gradual drop continued throughout the month of October, and Perry garnered just 10% of the vote by the time of the "oops" debacle on 9 November.

That moment may have cost Perry an extra few percentage points at most, but he was in the basement of the polls long before then. The real damage of "oops" is that it made Perry a nationwide laughing stock, but his candidacy had stalled terminally weeks earlier.

3. Newt Gingrich. There isn't one Newt Gingrich moment that helped him skyrocket to the top of the polls in late November. He was typically assertive, combative with the moderator, and brutal in his rhetoric towards President Obama in a string of appearances. There can be little doubt that Gingrich benefited greatly from these debates. Where Pawlenty and Perry were weak, Gingrich took charge. 

Gingrich employed the same playbook to make an almost unfathomable comeback just prior to the South Carolina primary. He turned in perhaps the second most memorable debate moment of the cycle when he attacked moderator John King for his questions over the saga of Gingrich's ex-wife Marianne's "open marriage" accusations. Gingrich won South Carolina by double digits.

But for all that Gingrich's debate performances seemed to carry such weight, Mitt Romney's campaign wealth and negative advertising seemed to overcome the Gingrich surge. As I've noted before, Gingrich led in the Iowa polls on 10 December. On the same day, he supposedly "won" an impressive victory in a debate. All the analysts said his poll numbers would continue to climb, but instead, he had lost his lead by 15 December. It turned out that those "memorable" debate performances were drowned out by negative ads from Romney's Super Pac. The same phenomenon occurred in Florida five weeks later. A good debate was trumped by attack ads.

4. Rick Santorum. In the cycle of the debates, it's noteworthy that the candidate leading in all the nationwide surveys right now has not had one standout debate performance. Rick Santorum didn't "win" a single debate before his Iowa rise. He was seen as taking the healthcare fight to Mitt Romney in an effective way in the last Florida debate, but it was Romney's attacks on Newt Gingrich that won the most plaudits from the press that night.

The truth is that Santorum has been fairly steady during most debates. He's never gotten the most press, but he's never been caught making a boneheaded error. In most years, a candidate like Santorum would have been long gone ? as Pawlenty was. Santorum is only around now because no one buried him when they had the chance, and the debates haven't given voters a reason to dismiss Santorum out-of-hand. He's perhaps most benefited from other candidates beating each other up ? leaving Santorum the last man standing. 

5. Mitt Romney. No candidate better reflects the tortoise in this race than Mitt Romney. His debating has been mostly reliable but unspectacular. Romney has attacked when he needed to (see Pawlenty, Perry, and the last Florida debate with Gingrich), and he has seen some improvement in his polling numbers when he's adopted a more aggressive stance. Mostly, though, he has tried to focus his attacks on President Obama.

One of Romney's weakest moments in a debate had no immediate impact on the polls. His $10,000 bet with Rick Perry on 10 December was maligned by pundits, yet he turned a deficit in the Iowa polls on the day of the debate into a lead five days later.

Romney's inability to field questions about his taxes in a 16 January debate did have an impact on the race in South Carolina. He saw his lead drop by 10 percentage points the day after the debate, and then lost the state altogether on 21 January, after another sub-par performance on 19 January. 

The interesting thing about that 16 January debate, though, is that many analysts didn't believe Romney had damaged himself that much. An article by influential liberal commentator Howard Kurtz, following the debate, was headlined: "Mitt Romney Shrugs Off Attacks, Emerges Unscathed in Fox News Debate in South Carolina."

Kurtz was certainly not alone, and this points to something important about debates. Whether a candidate does "well" or "badly" is often in the eye of the beholder. Yes, there are the rare "oops" moments, where we can all agree that something has gone terribly wrong; but usually, we can't.

Debates this cycle have helped to frame the overall narrative of the contest, but they are far from having been the determining factor. If they were, Newt Gingrich would probably have won Iowa. Other facets of a campaign such as advertising and establishment support have played as large a role, if not a greater one.

Wednesday night's debate may make all the difference in the world in the tight Michigan primary. It also may have no impact at all. We really have no way of knowing. The one thing the smart viewer should be weary of is taking the post-debate analysis at face value. It's been wrong before.

Covering the racism story for ITV, reporter Richard Pallot twice referred to black footballers as "coloured". The remarks led to dozens of comments on Twitter and prompted the broadcaster to issue an aoplogy.

An ITV News spokesman said: "ITV News apologises for the inappropriate use of the word 'coloured' in a report on racism and football in today's News at 1.30pm. We take this error very seriously and we regret any offence caused."

When hundreds of Syrians have already died under the relentless bombardment raining down on the city of Homs, it might seem invidious to single out one woman. Marie Colvin of the Sunday Times was not even the only foreign journalist killed in what was supposed to be a safe house. So, too, did a young French photographer, Remi Ochlik, while others were gravely wounded. But for more than 30 years Colvin had filed tough, humane, highly intelligent reports from the world's frontlines, the last only hours before she died. She nearly died in Sri Lanka in 2001, when she lost an eye: eight years later she was the first to report on the apparent murder of the last surviving Tamil Tigers despite their attempt to surrender. Just over a year ago, she addressed a service honouring colleagues killed in the wars of the first decade of the 21st century. She knew the risks. She believed that to bear witness, it was worth it.

History repeats itself, nowhere more so than in Somalia. As was widely predicted at the time, the Ethiopian intervention in 2006 did little more than galvanise radical Islamism. Clans who had fought each other for years united against the foreign invader, one which they had little difficulty in portraying as Christian. Five years later, after a series of bombings and cross-border kidnappings, Kenya deployed thousands of troops in Somalia's Juba valley in an invasion that was ill-thought out, ill-prepared, and with loose military objectives.

It was initially called an operation of hot pursuit; that became a mission to weaken al-Shabaab militants; and finally the deployment became open-ended. Kenyan troops are still there. Bogged down amid heavy rains and undependable Somali clans, despite some successes the force remains some way from taking the port city of Kismayo, where al-Shabaab earn its revenue. Faced with superior conventional firepower, al-Shabaab has melted away and used guerilla hit and run tactics. To cap this chronicle of failure, Britain and other EU countries are considering conducting airstrikes on al-Shabaab camps, particularly where the militants co-exist with pirates. The two problems are being conveniently conflated. Armed helicopters are being flown in from warships acting on unreliable local intelligence. It is a recipe for civilian casualties, which al-Shabaab would skillfully exploit.

Human Rights Watch in a new report this week documents the increasing use of child soldiers by all sides, but particularly al-Shabaab. This may reflect the military pressure they are under, or their loss of local support. But it also means that some of the soldiers at camps targeted in special operations could be children. Adult fighters who have shown no compunction abducting children from playgrounds, and throwing them into the frontline, will not shy from inviting such attacks.

Al-Shabaab is not a unified force, but an affiliation of militias. It could unravel in the right conditions. The one political organisation that was able, briefly, to unify south and central Somalia by transcending clan loyalties was the Union of Islamic Courts. But they were declared the enemy, and their forces defeated by the Ethiopian invasion. A succession of western-backed transitional governments, all dependent on foreign armies, have failed. The current transitional federal government is corrupt and its writ does not run far even in Mogadishu. When its mandate expires in August, it should not be renewed.

Somalia's root problem is governance. A federal structure that is to work will be loose and constructed from the bottom up. The donors and the UN agencies who will be represented at Thursday's London conference, who have spent decades working with discredited governments in Mogadishu, do not know which clan leaders to talk to. Somali clan politics work by consensus, and through representatives who establish a proven track record. Legitimacy is not built by elections. The donors are beholden to the countries that finance them, not the Somalis they supposedly serve. The two cycles of the emergency and of the western response are permanently out of sync with each other. At worst, the money that pours in as a result of the drought feeds the corrupt government that produces the next disaster.

Freelance military operations by foreign armies should end. If security is to be provided against al-Shabaab, it should come from Amison, the African Union Mission in Somalia, but that then needs resources. Military action cannot be taken without the support of local clan leaders. Further militarising the conflict could well see it spread to the north-east province of Kenya, where there are now 500,000 Somali refugees. MI5 fear a Somali-linked bombing campaign in London could follow. After two decades of war, Somalia can only find its feet under a coalition of regional groups and an absence of foreign armies. Drones and helicopter strikes are not equipped with political night-vision. A certain level of disengagement might be what Somalia needs.

McDonnell had previously said he would sign the bill if it was passed by the general assembly. But faced with growing opposition, McDonnell released a statement on Wednesday minutes before the bill was debated in the House, in which he said that, after discussions with lawyers, physicians and legal experts, amendments were needed to "address various medical and legal issues which have arisen."

Critics had pointed out that the bill, if passed in its original form, would have obliged doctors to carry out a procedure that risked breaking a state sex crime statute known as object sexual penetration.

State lawmakers passed the amended bill on Wednesday afternoon. It now explicitly states that no woman will have to undergo a transvaginal ultrasound involuntarily. Instead, it requires women seeking an abortion to have an external, transabdominal ultrasound.

The changes also include having a doctor ask the woman if she wants to see an image from the ultrasound rather than requiring a copy to be attached to her medical file.

In his statement, McDonnell said: "Mandating an invasive procedure in order to give informed consent is not a proper role for the state. No person should be directed to undergo an invasive procedure by the state, without their consent, as a precondition to another medical procedure."

But the revised legislation is still facing strong opposition, with campaigners expressing anger that it was passed at all. They said the ultrasound may be less invasive, but it is still an unnecessary medical procedure mandated by law, rather than at the discretion of doctors.

ProgressVA, a progressive advocacy group that said it had helped to gather 33,000 signatures in Virginia for a petition against the bill, said it was "heartening to see lawmakers begin to take Virginians' voices seriously", but added: "Instead of wasting more time amending these bills to try to make their constituents a little less angry, lawmakers should kill these bills and get back to work on Virginians' priorities."

This week, Virginia has come under increasing national scrutiny for moves to pass the legislation, the first of two of the most controversial anti-abortion bills in recent history proposed by state Republicans.

Democratic delegates said that the Republicans did not understand the science and said that they missed the opportunity to properly discuss it.

Charniele Herring said: "Governor McDonnell is still willing to sign a mandate to require doctors to perform an unnecessary medical procedure. That is unacceptable."

She added: "The way they rewrote it will require a woman to have an abdominal ultrasound. They missed the point of the science. The reason a transvaginal ultrasound is used an at early stage of pregnancy is that you cannot detect anything otherwise. They messed it up again."

During the debate, before the bill was passed, Jennifer McClellan, another Democratic delegate, told Republicans: "What you have done is mandate an ultrasound that is utterly useless. Early in a pregnancy the reason a transvaginal ultrasound is done is because if you do it externally all you see is muscle."

The reason for the governor's change of mind is unclear, although two officials told the Washington Post that some of the bill's supporters were apparently unaware of how invasive the procedure would be.

Other suggest that McDonnell's motivations are political. He is seen as a rising star in the party and a possible vice-presidential candidate, and so he is keen to avoid being associated with a measure that could be politically damaging at a national level.

The most practical ? or, at least, the more practical ? Republican candidate is, after all the high jinks, supposed to win, which has been the singular case for Mitt Romney. But it is now suddenly quite possible that the least-practical, most far-fetched figure, will pull it off.

This is a level of implausibility not just in the context of this campaign, but in history. There has never been a major party candidate as far from the norm as Rick Santorum ? unless, that is, he's about to redefine the norm. Not even Barry Goldwater, the rightwing hawk whose 1964 loss remains the Republican party's biggest ever, was this far from the mainstream.

If Santorum wins next week in Michigan and Arizona, now distinct possibilities, that would come close to assuring this fabulous outcome. It's a kind of development that the earnest and process-oriented political media ? believing that politics, by its nature, reflects the norm ? seem so far unable to characterize effectively. Even the hysterical and shambolic nature of the Republican field over two cycles has not seemed to prepare anyone for how to account for Rick Santorum's possible nomination. Everybody is still quite deadpan. Nobody's yet officially gobsmacked.

There's almost a kind of private joke aspect to what's happening here: the liberal press seems to have cagily and humorously exercised its bias by not piling on Rick Santorum, hence helping him and hurting the Republicans. Or the joke all along has been Romney: a candidate so perversely unlovable that every clown has been able, however briefly, to be his contrast gainer.

This is what we know: the anti-Romney ideal is much stronger than Romney himself. The combined anti-Romney numbers have won handily in every primary so far (even in New Hampshire, Romney's only big win, Gingrich, Paul, and Santorum beat him). And because politics is timing it is the last anti-Romney standing who could slay him?and that's Rick Santorum.

But perhaps there is an even greater, historic logic at work.

The Republican party, at least since its Ronald Reagan-era reconstitution, has cultivated its blood grievance against liberal values and lifestyle (in spite of Reagan's own personal lack of heart for this fight). Of the Republican party's two main themes ? the other being anti-tax and anti-state control ? the social fight has been the more animated and, arguably, the more heartfelt.

The true antagonism in the country is not about the administration of government, but about how we live, between new and evolving, and old and fixed standards of conduct. It's the most fundamental western debate: secular or not, reason or ritual.

It is hard to imagine a candidate who might more completely personify the God-driven, anti-scientific, father-centered, my-way-or-the-highway, throwback life than Rick Santorum. Even the most conservative politicians tend to live a pretty modern-world, yuppified life. Not Santorum. Part of his appeal, particularly against the ever-shifting and mollifying Romney, is that his shtick is real. Mind-blowing, but real. Not only does he have far more children than any modern, striving, trying-to-do-better American has, but he home-schools them. Home-schooling is one of those things I think most Americans understand: a true and arduous commitment, albeit one for weirdoes. You get it all with Santorum: the Christian nation; the traditional family; the sexual aversions (including one against contraception); the homemade theology.

It even seems likely that he wouldn't run from his primary-playing wedge campaign during the general election: what we're seeing now is what we'd probably get, no matter how cockamamie and dumbfounding.

In other words, this would be a campaign starkly pitting the two competing strands of American culture against each other. It's a remarkable opportunity: finally, a referendum on all things that have so upset the conservatives and have been so embraced by everybody else ? abortion; gay marriage; sexual license; the new family (or non-family) life. How could it not be? These are Rick Santorum's issues, his reason for being here. This is the debate, however futile, he seems to believe God made him for.

But what if? Elections are like jury trials. The outcome is necessarily unpredictable. What if Europe goes over the abyss and with it the nascent US recovery? What if Israel goes after Iran and gas goes to eight bucks a gallon at the pump? What if the unforeseen happens, and President Obama fumbles his response?

Then ? President Santorum? And a preposterous chapter in American history?

But then again, the compelling, if also train-wreck, aspect about Santorum is that it really does seem like he'd rather be right than be president. His wealthy Super Pac supporters seem similarly hell-bent (and rich enough not to need to worry about actually winning an election). No matter what happens and how much the Democrats might find themselves up against it, Santorum seems determined to make this an up-or-down vote for the way he is living and wants others to live, as opposed to the way most Americans have actually chosen to live.

That vote, by sheers numbers of people living by modern conventions, seems preordained.

The prospect of a defeat of this magnitude is obviously as horrifying to Republican leaders and stalwarts ? all who seem to be lining up in a panicky defense of Romney ? as Santorum's actual election would be to liberals. Although I'm not sure it should be. What happens to the Republicans after Romney tries to fashion a middling and, to conservatives, quisling general election position and is defeated (and who is expecting otherwise)? In four years, another round of eccentricity and exaggeration?

An up-or-down vote on far-out rightwing lifestyle prescriptions ? is the country for or against, and what by what proportion??is as good for the Republicans as for liberals. It marginalizes the margin.

Everybody has avoided this issue. The passion of the committed has been too great to face. They are a minority whose limited future has oddly fortified them.

So, finally, in a likely landslide of teachable-moment proportions, we can vote for how we want to live. That'll be a vote everybody will want to cast.

Another Briton, Jeffrey Tesler, a London lawyer, is due to be sentenced on Thursday after pleading guilty last March to his role in the bribery.

The prosecutions of the pair have been controversial as both were extradited from Britain under contentious legal arrangements between the UK and the US.

A series of suspects have been sent to the US under a legal regime which has been criticised for being unfair to Britons.

Chodan's conviction came on the same day the prime minister announced that Theresa May, the home secretary, will conduct a "proper, sober, thoughtful review" of Britain's extradition treaty with the US.

Chodan and Tesler were extradited to Texas after losing legal battles in the UK. Once in Houston, they pleaded guilty to conspiring covertly to bribing top-ranking Nigerian politicians and officials.

Both worked for an international consortium of construction firms seeking contracts worth $6bn to build a gas plant on Bonny Island off the coast of Nigeria.

Chodan, whose home is in the Somerset village of Nunney, was employed as a sales executive for a subsidiary of Kellogg Brown and Root during the conspiracy. He recommended Tesler as the consortium's middleman to pay the bribes.

Chodan and other conspirators "met with successive holders of a top-level office in the executive branch of the Nigerian government" to discuss how the bribes were to be paid, according to US prosecutors.

Tesler, 63, who operated from run-down offices in Tottenham, north London, admitted that he acted as a middleman for the consortium and routed the payments through bank accounts in Monaco and Switzerland between 1994 and 2004.

US prosecutors discovered that Tesler arranged for $1m in $100 notes to be loaded into a pilot's briefcase and then passed on to a politician's hotel room to finance a political party in Nigeria.

The authorities have seized $148m from Tesler's bank accounts. Chodan has agreed to forfeit $726,000 as part of his punishment.

The sentencing this week is expected to mark the end of a protracted effort to prosecute the conspirators for the corruption allegations, which surfaced more than eight years ago.

The Serious Fraud Office decided to step aside and let the US government prosecute the two Britons.

The Guardian is fighting a legal battle to gain access to official documents which were used to justify the extradition of the pair, but this move has been resisted by the British and American governments.

Over the past three years, US prosecutors have forced five companies from the US, France, Holland and Japan to pay penalties totalling $1.7bn for participating in the Nigerian bribery scheme. An American executive, Jack Stanley, is also due to be sentenced on Thursday in what is expected to be end of US prosecutions over the scandal.

In recent years, the American government has made great efforts to prosecute firms and their executives for paying backhanders to officials and politicans in other countries to land contacts.

Even firms whose corruption has only been slightly connected to the US have been prosecuted by the American authorities.

We welcome the decision of Khader Adnan to end his hunger strike against Israel's inhuman practice of "administrative detention" (Israel agrees release deal for Palestinian hunger striker, 22 February). His hunger strike was a desperate measure meant to draw attention to Israel's violations of international law by routinely abducting Palestinians and holding them without charge or being notified of the reason for their detention.

As you report, more than 300 prisoners are being held without charge in Israeli jails. These prisoners and the thousands who have been similarly detained are subject to inhumane and humiliating treatment and often denied access to family and lawyers. Israel applies this procedure on a large scale as a tool of political oppression. This is a grave violation of the fourth Geneva convention as well as the convention on civil and political rights, and the convention against torture.

Mr Adnan started his hunger strike on 18 December, protesting on behalf of all administrative detainees. His action has brought the issue to the world's attention and we must continue his campaign to end Israel's policy. We urge readers to make direct contact with the Israeli embassy and the foreign secretary, William Hague, demanding the immediate release of all Palestinian prisoners held without charge or trial.
Betty Hunter Honorary president, Palestine Solidarity Campaign, Ghada Karmi, Bob Crow, Ken Loach, Kika Markham, Canon Garth Hewitt, Geoffrey Bindman, Bruce Kent, Dr Salman Abu Sitta, Jenny Tonge, Karma Nabulsi, Rodney Bickerstaffe (PSC patrons)

Given the dangers of cycling in cities (Lower speed limit in towns would increase cycling ? poll, 20 February), one might think cycling in the countryside would be safer. But recent research commissioned by the Department for Transport states almost half of cycling fatalities in the UK occur on rural roads, where the risk of being killed while cycling is up to 10 times higher than the UK average.

The Campaign to Protect Rural England believes cycling should be attractive and safe for people in town and country. We have been calling for national funding of safe walking and cycling routes along busy rural roads. We are also campaigning for national speed limit guidance ? due to be revised later this year ? to be changed to make 40mph zones on minor rural roads the norm. This would mirror the approach by the Dutch, who have found that such measures have cut serious crashes on their rural roads even more effectively than new, lower speed limits in their urban areas.
Ralph Smyth
CPRE senior transport campaigner

Air strikes in Somalia will solve nothing (UK weighs up strikes against Somalia rebels, 21 February). First, the corruption and ineptitude that underpins the transitional federal government's (TFG) inability to act as a responsible instrument of the state facilitates al-Shabaab's control. This was seen last year when the TFG failed to seize on al-Shabaab's withdrawal from Mogadishu in August and the group returned in October with the detonation of a truck bomb. Air strikes will make no difference if the failures of the TFG go unaddressed.

Second, the piracy issue will not be solved by military force. Addressing the conditions that compel young Somali men to seize the profitable opportunities of the sea requires analysis of deep-rooted social impoverishment which has penetrated Somalian society for more than 20 years. Further militarisation may be tempting to treat the symptom, but it will not alleviate the cause.

Third, the international community's approach to Somalia insists on structuring the state around a centralised system. This is fundamentally flawed and underpins a deeply misguided understanding of the country.  

At the London conference on Somalia, policymakers should be mindful of these issues and move away from discussions of military action. They should look beyond the narrative of criminal piracy and think instead about the conditions which led young Somali men to this path. They should take direction from the Somaliland and Puntland experiences, and consider why the internationally backed solution has not worked. This doesn't require any special out-of-the-box thinking. But it does require some thinking.
Shireen Lau
Programme assistant at the secretariat of the Global Partnership for the Prevention of Armed Conflict

??The last 20 years have seen a litany of exclusive political deals between Somali elites and foreigners. These have shut out ordinary Somalis and made many disillusioned and angry. The international community desperately needs to change its approach and support a process that is led by a broad range of Somali stakeholders, with the outcome of the process made to work by them.

We in the international community feel instinctively uncomfortable with this as we don't know where it might lead. But in supporting a political settlement in Somalia we must accept that solutions may be unorthodox.

Now is the time to put into practice rhetoric about a process that is Somali-owned and driven. That means the international community facilitating the process, not steering it towards the outcome we want.

And we need to stop thinking and acting as though we ourselves have to find the Somali solution to Somalia's conflict ? we don't and we shouldn't. Somalia's eventual political settlement may well reflect a constellation of smaller Somali-owned settlements that together add up to an arrangement accepted by the majority of Somalis.

The London conference should be a launching pad to restart talks on the structural problems that Somalia faces. There are options, we just need the political stamina and openness to pursue them. 
Henry Smith
Director, Saferworld

That is what eurozone leaders insist they did this week. Their exhausting, day-and-night efforts must be acknowledged. They have worked hard to square many circles. It is easy to criticise from the sidelines. Nonetheless, this has to be said once again: they have not succeeded yet. It is not just, as the cliche has it, that they are still kicking the can down the road. Now they are kicking a Molotov cocktail down the road.

At the moment, there is still a solid majority in Greece for staying in the euro. Yet I find it hard to believe that the people of Greece can for months and years take the extreme pain demanded of them, with the only argument being "to leave the euro would be worse". The personal stories are already heartrending. The journalist, teacher, civil servant reduced to queueing at the soup kitchen. Students in a "lost generation" who have left the country or are about to. Unemployment at 21% and rising. An estimated 150,000 businesses that have closed. The minimum wage to be cut by more than one fifth. Thousands sleeping on the streets. The homeless by night; demonstrators by day. The octogenarian musician Mikis Theodorakis ? a favourite with generations of German tourists ? has called for an "uprising". And the government has to implement a bunch of further austerity and liberalisation measures over the next week, before it can get the ?130bn bailout.

Sitting at his regular table in the pub, his Stammtisch, the reader of Germany's tabloid Bild may still mutter, "Well, they have only themselves to blame." But he would be wrong. It is true that a very large share of the blame lies with irresponsible, deceitful and corrupt Greek policies and business practices. But the scale of this mess, and the difficulty of getting out of it, also results from the fact that Greece was accepted into a badly designed, over-extended eurozone; that the way bond markets and banks (including German and French ones) treated that eurozone positively encouraged such irresponsibility; and that this bailout is as much to help those banks as it is to help Greece. So the blame must be shared.

Even if you disagree with that, the responsibility for getting out of it is still shared. This is obviously true so long as Greece remains in the eurozone; but even if Greece leaves, it will remain a member of the EU, and there will be a moral and historical responsibility that derives from having got into this mess together.

Then there's that troublesome thing we call, from the ancient Greek, democracy. Many European leaders privately agree with the German finance minister, Wolfgang Schäuble, that it would be better if Greece did not have an election scheduled for this April. Democracy? Ask the people? What an appalling idea. But the Greek people will be asked. Unless they are shown some realistic prospect of growth, parties opposed to the draconian terms of the bailout may yet gain a majority. No one will then be able (though some may privately wish) to follow Bertolt Brecht's famous ironic suggestion: dissolve the people and elect another.

At that moment, Angela Merkel will have more than a year to go to her own general election, which she is self-evidently determined to win. The eurozone will then be torn between the maximum pain that Greek voters will accept and the maximum price that Merkel believes German voters are prepared to pay. That dilemma ? call it Merkel's fork ? is just the most critical example of the deeper problem of this eurozone: the contradiction between already European policies and still national politics. You could have close, similar economies and still diverse politics (the nordozone that might have been). Or you could have fairly diverse economies if you had converged politics, with one eurozone election for one eurozone government. That common politics would then allow for the financial transfers to compensate for differences, as in the United States, and work towards economic convergence in the longer term. What is unsustainable is to have, within a single currency zone, both divergent national economies and divergent national politics.

So far as I can see, there are only two ways out of this. One is that Germany, all other European governments (including Britain's), the European Central Bank, the EU institutions, the IMF and every other relevant player work over the next few weeks, like Mozart in his most inspired frenzy, do what every sensible political economist (including many in Germany) says is necessary: produce a strategy for short- to medium-term growth as well as fiscal consolidation and structural reform. For as Mohamed el-Erian, the chief executive of the giant bond investment firm Pimco, observes, this week's agreement "leaves Greece's basic problem unresolved. The country still faces the prospect of too much debt and way too little growth."

That strategy for growth must not only be found, it must be seen to be found ? seen by Greek voters, that is, before the next election. The other alternative is that, sooner or later, Greece leaves the eurozone. The former is more desirable, the latter more probable.

Twitter: @fromtga

Ringer's delightful episode title, What Are You Doing Here, Ho-bag?, refers to the introduction of another new character for Bridget/Siobhan to pretend to recognise/get to know: Juliet's mum (and Andrew's ex). Even though this is only the 12th episode, this show has had so much going on (fake junkie hitmen/pretend pregnancies/disappearing frenemies), that the return of evil drug dealer/strip club owner Macawi (you know, the one that got Bridget in this complicated mess in the first place) is almost a surprise. Richard Vine

Kidnap And Ransom
9pm, ITV1

In this second series set in the crisis-stricken Kashmir, Trevor Eve's negotiator finds his efforts to secure the release of a British Asian family hampered by the violent interventions of local police. The two kidnappers, Anwar and the mysterious, somewhat nervous Leela, take the family's son, Mahavir, and then hijack a tourist bus. There's a faint undercurrent of Celebrity Road Trip about the collection of hapless passengers, who include Kimberley Nixon (Fresh Meat) and Christopher Fairbank (Auf Wiedersehen Pet) but it's Eve who dominates, caught between desperate kidnappers and trigger-happy police. David Stubbs

This World: Fukushima
9pm, BBC2

Around this time last year, Japan nearly contributed a third city to the list of those destroyed by nuclear technology. In the aftermath of the tsunami, the nuclear plant at Fukushima suffered a meltdown. This was bad ? indeed, the worst nuclear accident since Chernobyl ? but as this terrifying film's interviews with survivors, employees, rescue workers and the prime minister of the time make clear, it could have been calamitous. The consolation is this chance to admire the courage and ingenuity that averted disaster. Andrew Mueller

The Great Ticket Scandal: Dispatches
9pm, Channel 4

It's a familiar tale: you try to get tickets for a gig or event, only to be left empty-handed when it sells out in minutes. So how come there are tickets available online at inflated prices ? and who is selling them? Morland Sander investigates the business of ticket reselling, and undercover reporters try their luck on two major fan-to-fan ticket exchange websites to find out who is profiting and how they get away with it. Hannah Verdier

Pramface
9pm, BBC3

BBC3 wanted a new Gavin & Stacey. All it got was this lousy straight-to-DVD Knocked Up/buttoned-up Inbetweeners/Skins. In attempting to be all things to all viewers, this first episode fails to come close to any of them. Laughs are thin on the ground, and a bedroom wank scene manages to be boring. With some quality cast members ? Angus Deayton is a shady father and Submarine's Yasmin Paige is the precocious and lovelorn best friend ? we're still hoping Pramface can find its voice. Clare Considine

Catholics
9pm, BBC4

A new three-part series in which film-maker Richard Alwyn investigates what it is to be a Catholic in modern Britain. The episodes are themed around men, women and children: the first takes a behind-the-scenes look at Allen Hall seminary in Chelsea, following those men who have been called to the priesthood. These include an ex-roadie and a former law practitioner; both have signed up for a minimum six years of training, this at a time when the number of applicants is in severe decline. It's a fascinating insight into how priests are made, and why they choose to devote their lives to the Church. Martin Skegg

Britain is an obvious target for Russian espionage, given the large number of Russians who live and work here. After defecting, Karpichkov needed a new outlet for his talents. He mounted undercover commercial investigations into several high-profile Russians living in London including, he says, Boris Berezovsky and Roman Abramovich. He also found himself drawn to the Kremlin's overseas spying operation in London. At one point he infiltrated a pro-Putin youth group, Marching Together (later renamed Nashi), as it sought to undermine and discredit Russian exiles opposed to the Putin regime. The group's key targets included Litvinenko, the Chechen separatist leader Akhmed Zakayev and Boris Berezovsky, the oligarch and Putin critic embroiled in a colourful high court litigation battle with Roman Abramovich.

Karpichkov agrees with the head of MI5, Jonathan Evans, that the number of undeclared Russian intelligence officers in London hasn't decreased since the end of the cold war. "Britain is a prime target for Russian intelligence services," Karpichkov says. In the years after 9/11, Britain's security services turned their attention to combating Islamist extremism. They assumed that the Russians would do the same, and scale back their operations in the UK.

They didn't.

But it is an open question how successful much Russian espionage actually is. The Russian deep-cover agents exposed in the US in 2010, including the glamorous Anna Chapman, now a cheerleader for Putin's United Russia party, seemed more bungling than sinister. Similarly, many of the Kremlin's British operations, apparently aimed at influencing public opinion, come across as primitive and ridiculous.

In 2004, Karpichkov met two Nashi representatives sent by Moscow to London ? "Alvis" and "Irina". He didn't reveal his real identity. "Alvis" and "Irina" paid demonstrators £4.50 an hour in cash to take part in various pro-Kremlin rallies in London: one against Zakayev, another against Anna Politkovskaya, murdered two years later by an unknown hitman in the stairwell of her Moscow apartment.

According to Karpichkov, Nashi also targeted the actor and political activist Vanessa Redgrave, a close friend and supporter of Zakayev's. In late 2004 the pro-Kremlin group organised a fake "demonstration" in a park close to her Chiswick home. That evening unknown intruders damaged her front door. Redgrave complained to police. Karpichkov alleges that the damage was caused by elements within Nashi. He also claims Kremlin activists were behind an October 2004 attack on the neighbouring Muswell Hill homes of Litvinenko and Zakayev; someone lobbed molotov cocktails into their gardens.

And what of Livineko's polonium murder in November 2006, killed by a cup of radioactive tea? Karpichkov says he has no doubt that his old employer, the FSB, was behind it. He also says that he warned the British intelligence services via intermediaries that Litvinenko's life was in danger. The agency politely ignored his advice, he says ? a "negligent" decision that allowed a Russian hit squad to kill him.

Karpichkov also claims that a Russian diplomat based at the Russian embassy in Kensington, west London, was involved in the Litvinenko operation and died mysteriously afterwards.

The three men who allegedly poisoned Litvinenko ? Andrei Lugovoi, Dmitry Kovtun and Vyacheslav Sokolenko ? are all former members of the KGB's Ninth Directorate. According to Karpichkov, other KGB departments regarded "niners" as little more than jumped-up bodyguards, providing protection to top Kremlin officials. He believes someone else ? an unidentified fourth person ? flew to London to mastermind Litvinenko's poisoning. They then flew out again. "It [an overseas assassination] is quite a sophisticated process. They would have needed someone with brains," he explains.

These days Karpichkov tries to keep a low profile. He writes, stays in touch with events in Russia and vanishes now and again on mysterious trips whose purpose he declines to explain. But, I suspect, he is never able to relax.

Unsurprisingly, Russian agents working at the London embassy keep an eye on him, he says. There have been anonymous death threats, bugging and cars with Russian diplomatic plates repeatedly parked outside his London flat. Old habits of suspicion are hard to shake.

After we meet at Marble Arch, we go to a nearby cafe; Karpichkov, however, suspects that someone sitting at the next table is listening in; we leave and stroll instead among Hyde Park's plane trees. Karpichkov is used to exile now but my sense is that even after a decade in London he has to live by Moscow rules ? to accept that he will never be able to relax fully, or to forget his old instincts and training in counter-surveillance. We exchange emails over a period of several months after our initial meeting. Karpichkov, it turns out, knows a huge amount: about Russia's murky arms sales abroad, for example. He is intelligent, and a first-class analyst ? but, of course, he has no one to report to.

Karpichkov says he is "no way scared". But he confesses he is now "dead tired" of the exhausting world of espionage, and concerned for the safety of his wife and grownup children. It strikes me that his story has little in common with the glamorous fantasies of James Bond. It is more similar to the drab, amoral universe of John Le Carre, with its lack of heroes, and atmosphere of slow, psychological attrition.

And what of rich Russians buying up British institutions? Chelsea FC, Waterstones, the Evening Standard and Independent newspapers are all now owned by wealthy Russians. Karpichkov is scathing about Alexander Lebedev, the billionaire turned British press baron, who worked as a KGB spy in London during the Gorbachev period. Lebedev's son, Evgeny, acquired British citizenship in 2010 and lives in London. "Lebedev pretends he is a liberal in Russia," Karpichkov says. "But we have a saying that he [Lebedev] will never piss against the wind." The wind of course is Putin. Putin, meanwhile, is certain to win Russia's presidential "election" next month, despite the biggest protests against his rule since the fall of the Soviet Union. So far he has made few concessions to the demonstrators, whom he has dismissed as western stooges.

As for Karpichkov, his application for asylum was rejected by the authorities, and it was only in 2010 that he finally got a British passport and permission to remain, a decade after he arrived in the UK.

Karpichkov says he is unimpressed by the way that MI5 last year tried to deport Katia Zatuliveter, the 26-year-old parliamentary aide and lover of the Liberal Democrat MP Mike Hancock. The home secretary Theresa May accused Zatuliveter of spying for Moscow, and tried to deport her on the grounds she was a threat to national security. "They looked like stupid little amateurs," he says of MI5, which failed to convince a special tribunal that Zatuliveter was shipping British secrets to Moscow. "If you are trying to prove a case you need to have strong evidence," he says, adding that he doesn't think Zatuliveter was ever a "classic staff agent". Nor does he believe she was on the payroll of the FSB, or the SVR, Moscow's foreign intelligence service. (The two agencies are fierce rivals, with the FSB authorised by Putin to conduct its own secret missions ? and assassinations ? abroad.)

We part in Hyde Park. No one appears to have been tailing us. There are no figures skulking behind the trees. But I find myself glancing over my shoulder, just in case.