Tonight will be a historic night in UK General Elections. For the first time, the leaders of the three main parties - Gordon Brown, David Cameron and Nick Clegg - will debate, live, with each other on national television. For an hour and a half, they will be under intense scrutiny; the media and the public on the look out for every word, gesture, killer line, gaffe, glance at the watch, blush...
The fact that we're having these debates probably reflects just how close this election is. Tony Blair refused to debate in all his elections. He had too much to lose. John Major, William Hague and Michael Howard wanted to debate because they knew Tony Blair wouldn't risk it and the election was out of their hands. This time, they all know it's a gamble. But the elction is a close one; and they're stuck with it.
Brown will be dreading it. He was ill at ease for the first two years at PMQs. He has a legion of gaffes and non-answers behind him. The YouTube smiley face disaster. Refusals to answer questions on boom and bust, the election that never was, the released Lockerbie bomber, the McBride affair. He has agonising experiences on GMTV under his belt. His answers are long, verbose and too focused on stats.
Against Cameron the PR man and Clegg with his nothing to lose, easy charm; Brown's appearance is a nightmare in waiting for the Labour party. Brown has more presentational weaknesses to resolve than any other candidate. But with expectations low, just one glimmer of humanity or charm from Brown could register with the voters.
Cameron's expectations are sky high. He needs to perfom well, but not come over as the slick PR man. He needs to get into the detail. But his history stands him in good stead - cool under pressure, speaking without notes, when in an almighty hole in September 2007; Cameron produced a hugely impressive party conference speech that made Brown cancel the election. He will have rehearsed immaculately.
Clegg should enjoy himself. He clearly knows his stuff. He's not the same Clegg that blundered over the "thirty quid" state pension. He needs to look different, but he should ease himself into this first debate and simply use the opportunity to get his messages across.
In an election that has yet to engage people, he might just inspire the voter who has given up on the idea of an uninspiring choice between Cameron and Brown. If he plays into the anti-politics audience, presents himself as wanting something different - he might just find people agree with him. He has no baggage - an advantage and a disadvantage. If those without an opinion of him (good or bad) see him mess up - they will come to a conclusion pretty quickly. There will be no other baggage to persuade them he was "having a bad day, is OK really".
The verdict? Utterly unpredictable. All the leaders have their form; with Brown's looking dodgiest. But any one of them could screw it up.
In the end, as with the Chancellor's debate, it is more likely to be sterile - with every candidate playing it safe. The stakes are just too high.
PREDICTION: Cameron to edge it, Clegg a close second, Brown third. Brown likely to disappoint with long, unsympathetic or fake answers and dodgy body language.