Channel 4 kindly asked if I would like to come and blog from the green room at this mildly historic event. So I said yes.
Already I have seen Quentin Letts, Polly Toynbee... and Lord Bragg struggling to get out of the building with his swipe card.
Still, I expect it is Security or Health and Safety or something, and he is a Labour peer. So welcome to the world you made, Melv.
So what are the prospects for tonight's event?
In a strange way, Vince Cable has the most to lose. So high is his reputation, that anything less than a display of extraordinary erudition will leave his fans disappointed.
But I have every faith in him. He is as the ability to appear above the fray whilst putting the boot in nicely. He will be fine.
Conversely, George Osborne has the most to gain. He is 38, yet I still find it natural to make jokes about hoping that someone has made sure he has washed his knees and pulled his socks up. is there more to him than the bright schoolboy? We may see tonight.
[Journalists gossiping next to me: There are stories in circulation about Tony Blair receiving hundreds of pounds worth of gifts and not declaring them.]
And Alistair Darling? He is slowly winning over the press as a great survivor. Given that he is the minister who introduced pension the 75p pension increase back in 2000, you can see their point.
Gordon Brown's announcement, albeit through gritted teeth, that he will continue as Chancellor, should Labour win the election, will have strengthened his hand.
Of course, I could have done this from home watching the TV - which is all I am doing here - but they do give you free coffee.
Polly Toynbee, for it is she, is being asked on TV how far this debate will set the scene for the leaders' debates in the general election proper. I suspect the dynamics will be different here. Nick Clegg may struggle to get into the debate: Vince, I suspect, will have no such problems here.
@channel4news has just tweeted:
EXCLUSIVE: Key themes on #askthechancellors agenda are 1) public finances, spending cuts, tax rises, 2) banks, bonuses & regulation, 3) jobs.Channel 4 News now reporting that no oil has been found off the Falklands.
That's my suggested economic policy buggered.
Someone has just reached Liberal England by searching for "big cats in Ratlinghope". Hello Shropshire!
Channel 4 Ask the Chancellors page.
Here we go!
The set makes it look like a rather dull quiz show.
First George Osborne. Deal with debt. Cut waste. In favour of enterprise and hard-working people.
Vince Cable. We warned about the bubble. There have to be cuts. The banks must lend to good British companies. Hard work, thrift, fewer prima donnas. Tax cuts for lower earners paid for by taxes on rich.
Alistair Darling. We can get through this provided we continue to support people. Get borrowing down to cut deficit, but protect front-line services. Secure jobs in the future.
That more or less confirmed what we already think of them.
What personal qualities do you have that will make you the best Chancellor?
Vince Cable: A lot of experience. I warned about the boom. When the crisis came, I advocated policies that the government, to its credit, did adopt.
Alistair Darling. Tenacity. Had to deal with unimagined problems to ensure the banks could open the doors the next day. My judgement has been right. His sense of fairness drives everything he does in politics.
George Osborne. Shadow Chancellor five five years. Part of a team. His values are support for people who work hard and save hard. it is not my money.
And he keeps his desk tidy.
Why don't you come clean on cuts?
Darling: I will at the next spending review.
Osborne: "We are all in this together." That never caught on, did it? I was the first to call for cuts. We cannot afford benefits to the rich. "This is our national debt." That certainly won't catch on.
Cable: We have set out £15bn of spending cuts, only party to do that. Defence cuts, including Trident. Swathes of bureaucracy overrunning local government. Surveillance state.
Now they are being allowed to debate this between them. Osborne saying we need cuts and everyone agrees with him. Oh no they don't, says Darling. You have been calling for spending cuts, but instead (muffed this a bit) you use the first spare money you find for tax cuts.
Vince gets first applause from the audience for talking about Osborne's "fictional savings".
Osborne getting snotty already. Not coming over well.
Vince now making Darling answer questions like an examiner. Class.
Will cuts be deeper than Thatcher's?
Yes, yes and yes.
Can you guarantee that NHS services will not be harmed by cuts?
Osborne. David Cameron asked me to ensure that we spend more every year.
Darling. We have doubled expenditure on the NHS. We will keep to the standards we have established.
Cable. None of us can give a guarantee like that. If we save money on NHS admin it should first go to neglected areas like mental health. But you cannot ring fence health or you will have massive cuts elsewhere.
Osborne name checks David Cameron again on NHS spending. A sign of his strength or weakness on the subject?
Will you cut pensions?
Darling people must be treated fairly.
Osborne. A cap on big public sector pensions. Audit how much public sector pensions are costing within week.
Cable. It is outrageous that highly paid public sector employees (including MPs) have such large pensions. This needs cross-party agreement.
Nice Darling dig at Osborne over lack of consensus on social care.
Vince calls for cross-party approach to whole crisis. (Can I be Chancellor please?)
Osborne having second go against "death tax". So how will you pay for it, posh boy?
Osborne still doing it. Trying to patronise the Chancellor. Failing.
Will you increase income tax or VAT?
Vince: We will cut income tax for lower earners. About £700 a year for average earner. Fully costed package.
Osborne: There will be some tax rises, but we will stop National Insurance increases.
Darling: No one wants to increase taxes, but... If I promise to cut taxes you will ask how I can afford to do it.
Osborne scores point against Darling, but it is Darling who gets the applause with a smart reply.
Vince says we are going to have a difficult decade. We have to keep society together and be fair. The rich must pay a bit more.
Cable asks Osborne if he supports a tax on banks to pay for public support. A little beside the point.
Can they rule out VAT increase? Darling, no. Cable, no but it would be dodging the question if we did.
Missed a question there, but Osborne using a Blairite "many and few" construction. Had to mentally check himself that he was getting it right.
Cable we are being held to ransom by super-rich. "Pin-striped Scargills." Clap, you buggers.
Darling. People can move around more these days, but there is no sign we are scaring them away.
Is it the Chancellor's job to make us more equal?
Both talk about "fairness".
Osborne: Sort of says yes. Interesting.
Darling defends tax credits to wealthier families. Hard to see how they help the poor.
Vince has a dig on inheritance tax and gets applause.
Question on bankers' bonuses
Vince good reply on splitting investment banking from high street banking.
Darling: Bonuses should be for good performance not taken for granted. But defends big banks. That's socialism for you.
Osborne: Bank tax now, even without international agreement. Attacks head of Barclay's.
Battery getting low
Vince: Banks must lend more to businesses.
Osborne: Bank regulation must change.
Both painting Darling as weak on this.
Question: None of you predicted banking collapse. Why should we trust you now?
Darling talks about future.
Osborne: The Tories did worry about debt.
Cable: Some of did want - and he applauded for it. Every demutalised building society has collapsed. But it was worse - "such greed and incompetence" - than he imagined.
Student scared of future. Will I get a job and be able to buy a house?
Osborne: More student places (eh?) Better help for unemployed. "A work programme." Diverting the rivers of Central Asia to water the Uzbek cotton fields?
Darling: There is some good news - offshore wind technology. If government works in partnership, there will be jobs in future.
Cable: Government cannot create jobs but we can make sure that the banks lend to the companies that do. Some public works on renovating old properties. But some of the cuts we are going to make will affect jobs.
Osborne says much the same thing now.
Darling: We have made the right judgement calls over the past two years. We will work with private sector to create jobs. Trust us.
Cable: Financial discipline, make banks lend. Who do you trust? Labour got us into this mess. Remember the Tories. Dig at rich backers gets applause. We are not beholden to super-rich or unions. We want change - but it has to be a change for better not the worst.
Osborne: There will be a Conservative government or a Labour government. We have the ideas and energy. It is your choice.
And that is it.
No big winners or losers, which meant that it was good for the Lib Dems as Vince's reputation will remain high.
Interesting that it was the left-wing points that got applause. The audience was very carefully politically balanced, so that may be significant.
Just met Chris Huhne: "a clear win for Vince."
Now for the train home...
Much later. Home again in Market Harborough.
Several days later. This became the raw material for a House Points column in Liberal Democrat News.