11:45 - Good morning one, good morning all, and welcome to a prime minister's questions in Westminster overshadowed by events across the River Thames. The PM has already made clear how "saddened" he is by the helicopter crash in Vauxhall, and we can expect there to be more comments about the incident in the main exchanges, which aren't far away now. We're starting this live blog a little late because of our coverage of the crash. But our news coverage this Wednesday has also been dominated by another strange story - horse meat in burgers - and the appalling state of relations between the civil service and ministers. There is half a chance Ed Miliband will want to mention the latter, but the appalling breakdown of trust between senior civil servants and the coalition's head honchos isn't entirely about politics. Tony Blair's comments about the issue will be in David Cameron's preparation folder, that's for sure.
11:57 - In the Commons right now, Stephen Crabb, who has a beard and is quite young, is answering questions from the despatch box. He is a Welsh Office minister, in case you weren't aware.
11:59 - One very obvious option for Miliband to go with would be Europe - only an hour ago Tory MPs launching their 'Fresh Start' campaign were presenting their party leader with a monstrous headache. He will be delivering his Europe speech on Friday, so this would be a good time for the Labour leader to prod Cameron about the issue dividing the Tories. THe only problem is, Europe doesn't exactly unite Labour either.
12:01 - Big Ben is bonging 12 noon outside, which is worrying, because my clock is showing 12:01. Oh well. Nearly time to start now. The Commons chamber is packed, and David Cameron is in his place. Stephen Crabb is doing very well, enjoying the stage as he gets an unusual amount of attention from his colleagues.
12:03 - And off we go. The PM pays tribute to a fallen soldier in Afghanistan. Cameron also mentions the helicopter crash in central London. He praises the emergency services for their "rapid and professional response to this situation".
12:04 - John Glen, the Tory MP for Salisbury, tees Cameron up with an easy starter for ten on pensions and the "grave injustice" of whatever it was Labour did. Cameron says the single-tier pension is an "excellent reform".
12:06 - Right, time for the main exchanges. Here's Ed Miliband, who also pays tribute to Sapper Reginald Walker. He raises Europe - aha! A very funny opener, getting lots of laughs from the opposition benches, as he wonders whether the days of "banging on about Europe" are over. Cameron responds by being all statesmanlike - a very effective response. "This country faces a choice," he says, in serious mode. Lots of theatrical arm movements from the PM, there. The Tories liked that.
12:08 - Miliband is all chirpiness in response, being thoroughly sarcastic as he congratulates "the Rolls-Royce operation of No 10 Downing Street". Cameron responds with some congratulations of his own, on Miliband's decision to keep Balls in his job until 2015. Balls grins at that - or maybe a smirk might be a better description. The PM then asks Miliband what his choices are on Europe.
12:09 - Next Miliband raises the 81-rebellion Cameron suffered on Europe. Cameron attacks EdM for focusing on "process" and says he's not interested in substance. He says the British people would be given a "false choice" if an in-or-out referendum was on offer now. The PM says the Germans and Spanish will be looking out for their national interests, so Britain should too. "Let's get on to the substance and give up the feeble jokes," Cameron finishes. Miliband continues probing, raising the prospect of five years of businesses facing a "closed" sign around Britain. Next Miliband quotes Michael Heseltine - very neat.
12:11 - "It is absolutely no secret that when it comes to Europe there are differences between myself and Michael Heseltine." Cameron deftly deals with that by pointing out Heseltine supported Britain joining the single currency. He then moves to the offensive, suggesting it's in "Britain's national interest to make the European Union more competitive and flexible" - he's giving away a lot more of his speech here, I think.
12:14 - Miliband comes back strong, accusing Cameron of having "lost control of his party". "He adds: He thinks his problems on Europe will end on Friday - they are just beginning." Next he wants to know if he's given the "green light" for different Cabinet ministers to take different views. The PM ignores that, claiming Miliband is "completely isolated on Europe". He continues the offensive, much to the outrage of Labour MPs. Miliband simply responds by saying he didn't ask the question about Cabinet ministers. "What is he doing? He's spent six months preparing a speech to create five years of uncertainty for Britain. When it comes to Europe, it's the same old Tories - a divided party and a weak prime minister." Cameron tries to come back strong, but he's being drowned out by Labour MPs. After Bercow intervenes, Cameron says the choice at the next election is simple: if you want to join the single currency or give power away, vote Labour! Um - that's almost certainly not true. But Tory MPs don't seem to mind...
12:16 - That's the end of the main exchanges, which were very energetic and lively. Both Cameron and Miliband were on form. But their failure to answer the others' questions means this was probably a 3-3 draw. Or something.
12:17 - Meanwhile, Laura Sandys raises the horse meat story, calling it "extremely disturbing news". The Food Standards Agency have told him there's no risk to public safety - "but this is a completely unacceptable state of affairs".
12:18 - Kate Hoey, the Vauxhall MP, raises the helicopter crash in her constituency. She's asking rather a long question, but gets lots of attention as she demands a closer look at how helicopters fly through the centre of London. Cameron says the "terrifying pictures" on the TV underline the points she makes. "I'm sure they will be looked at," he says.
12:19 - On food banks, Cameron points out their use went up under the New Labour government, too. He's been asked about this for the last three PMQs now, I believe.
12:20 - The mood in the Commons chamber remains very turbulent, but Cotswolds MP Geoffrey Clifton-Brown soon deals with that with a constituency question about funding for an important, but not especially politically controversial, college. Cameron, whose Witney constituency neighbours the Cotswolds, says he's happy to talk about this. He's reading from a pre-prepared response - something loyal Tory MPs will always help him out with.
12:23 - Jeremy Corbyn, the Labour lefty, raises housing benefit caps and related issues for poor people struggling in the capital. He's getting a lot of heckling from Labour MPs here as he repeats the government's position.
12:24 - Alan Reid, the Lib Dem backbencher, is worried by energy bills going up and those on benefits being hit as a result. Cameron focuses on helping people get a good deal for energy prices. Then comes Keith Vaz, the home affairs committee chair, who raises a diabetes question. He's worried by people consuming cans of Coke and Pepsi, which contain up to eight teaspoons of sugar. If we don't act now, the next generation will be overwhelmed by a diabetes epidemic". That sounds like a news story to me. Cameron replies by saying Vaz is right to raise the issue. That will have the soft drinks lobbyists pressing the panic button.
12:27 - After a question on knife crime, Rob Flello - the Labour backbencher - raises the European arrest warrant. He's not happy that Tory MPs want to undermine it. Cameron very smoothly dodges that one by saying the British can pick and choose which bits of Europe they like, and which they don't.
12:28 - Another loyalist question from a Lib Dem - this time from Annette Brooke. When was the last time a question from a Lib Dem MP actually caused any kind of significant response? It's been a while, that's for sure.
12:30 - Douglas Carswell, the Tory radical, shows the Lib Dems how it's done by complaining about the lack of all-postal primaries. This was in the coalition agreement, but not in the midterm review. Cameron says he does support them. "I hope that all parties can look at this issue and debate and see how we can encourage more democratic participation." A rubbish answer, there, which doesn't do anything to change the impression the coalition has completely lost interest in one of its original promises. So much for political reform.
12:32 - Margaret Ritchie, the SDLP MP for South Down, warns against Cameron's EU speech undermining relations with the US. The PM responds by warning the wrong thing to do is "bury your head in the sand". He's looking for the consent of the British people "to settle this issue once and for all".
12:34 - Well, I think we've just about got the measure of this week, and John Bercow brings the session to an end. One of my colleagues has just come in from the chamber (I'm at the other end of the corridor) and noted that when Cameron made all those points about Europe, none of his backbenchers were cheering. Interesting...
12:38 - And now here are some more wise words, from politics.co.uk's own Ian Dunt. He says Tory backbenchers were looking "extremely glum". Whereas I suggested it was a score draw, the political impact of this session might mean it's a win for Cameron, after all. Dunt adds: "They know it's a mess - some of them even have a bemused smile, but they're not exactly getting behind their leader, are they?"
12:40 - And with that, I'm wrapping up. In literal as well as figurative terms, for after I've closed this live blog I'm going to put on my jacket. It's freezing in here...