Tony Blair is facing the longest day of his political life with the vote on tuition fees swiftly followed by the Hutton Report.

Parliamentary Correspondent Rob Merrick looks at the Prime Minister's chances.

IN the TV thriller 24, Jack Bauer warns viewers he is facing the longest day of his life. It is a sentiment Tony Blair must share this morning. The secret agent had just 24 hours to stop a nuclear bomb exploding. Now the Prime Minister has the same time period to prevent his premiership imploding on him.

Tomorrow evening, scores of Labour backbenchers will vote alongside the Tories in a bid to stop variable university fees in a contest Labour whips insist is "too close to call".

And, on midday on Wednesday, Lord Hutton will unveil his long-awaited report into the death of Dr David Kelly. Nobody is pretending they know for certain what that will say.

All in all, if you see Mr Blair shivering outside Number Ten tomorrow it may not be simply because Arctic temperatures have gripped the capital.

Yet the feeling persists at Westminster that, just as Bauer saved the world for another money-spinning series of 24, the Blair show has many episodes yet to run.

But that doesn't mean the Prime Minister will emerge stronger from the wreckage of these two mighty clashes. In fact, the opposite will surely be the case.

First the fees furore. The hardline opponents of the Government's plans are still talking up their chances tomorrow night, but there is no doubt that their number is shrinking.

The reason is simple and for once it is not the arm-twisting of the whips.

The pill of variable fees has been so sweetened by the concessions offered to backbenchers that many feel they have to swallow it.

Consider what is at stake. The scrapping of upfront fees, a package worth £3,000 to the poorest students and a kinder repayment schedule. No wonder many rebels have changed their minds.

Of course, in dangling those carrots the Prime Minister has almost wrecked the original purpose of the Bill, which was to raise desperately-needed cash for the hard-pressed universities.

Mr Blair continues to boast that £1bn a year will be raised. What he doesn't mention is that the cost of the concessions is also £1bn. The vice-chancellors are practically in tears.

The huge cost makes it all but certain that, within a few years, the universities will again be pleading poverty and demanding that the £3,000 cap on fees is lifted.

It is the thin end of the wedge that the rebels fear. But the Government has offered a vote before the cap can be lifted and it seems to have bought off a sufficient number to save the Prime Minister.

Many flaky MPs fear that opposition to fees is a figleaf hiding a plot to oust the Prime Minister himself and that has contributed to the momentum slipping away from the rebels.

The leaking of a memo from one rebel leader, George Mudie, to another, Barbara Roche, about how wavering rebels should be "dealt with" provoked anger and backfired badly.

Backbenchers opposed to the variable aspect of the fees also have the option of voting for the Bill - and the juicy concessions - at second reading tomorrow and trying to amend it later at report stage.

Late last week, Government whips were spinning furiously that the vote could still be lost. The truth is surely that they feared only that victory was now being taken for granted.

However, if the vote is lost, then the Government has insisted the Bill will not be withdrawn which would make a dramatic vote of confidence all but inevitable.

That is when the true scale of the Blair-haters, those determined to get rid of him at all costs, will be revealed - and, I suspect, revealed to be very small.

This is the most successful leader in the Labour Party's history. It is hard to believe that more than a couple of dozen of his MPs will refuse to back him in such a showdown.

Mr Blair even has the option of tagging the Bill to the confidence motion, the method by which John Major finally squeezed through the Maastricht Treaty. But that would be a high-risk strategy.

A defeat on the fees vote would be hugely damaging, but probably survivable. However, a verdict from Lord Hutton that he had lied would surely spell the end for the Prime Minister.

From the evidence of last summer's hearings, there would appear to be no shortage of possible "smoking guns" should the judge wish to fire one.

As Michael Howard has pointed out, the Prime Minister is on most shaky ground over his claim that he had nothing to do with the naming of Dr Kelly to journalists as the BBC's source.

That was blown out of the water by the evidence of Sir Kevin Tebbit, permanent secretary at the MoD, who said the Prime Minister had chaired the decisive meetings.

Whatever mistakes were made by the BBC, there is also a mountain of evidence of how Downing Street put pressure on the intelligence agencies to "sex up" the now famous dodgy dossier.

What the hearings revealed was that the Government knew all along that the 45-minute claim referred only to battlefield shells - not to long-range weapons.

That meant there was no threat to British bases in Cyprus. Yet the Government encouraged the press to report under headlines screaming "45 minutes from attack".

Mr Blair described the threat as "serious and current". At the same time, Hutton uncovered, his foreign affairs advisor was admitting it "does not demonstrate a threat, let alone an imminent threat".

The key question is whether Hutton will go for the jugular. And here old Westminster hands remember the lessons of the arms-to-Iraq inquiry that threatened John Major's premiership.

The Scott report convicted the government of a cover-up that would have sent innocent men to jail. But - crucially - it said there had been no "duplicitous intention".

The suspicion is that, similarly, Lord Hutton will not want to bring down an elected Prime Minister. Blame will be shared around and alternative words found that don't quite mean liar.

So, like the hero who survives his longest 24 hours, Mr Blair will probably still be standing as the credits roll. What will it mean for the future? For Labour's modernisers, the signposts will be clear. A top-up fees victory opens up the prospect of other once-unthinkable changes - maybe hospital bed charges, or fees for GP visits.

We all know the Prime Minister likes nothing better than beating up his own MPs, but it's hard to see him getting away with taking on ever-larger numbers in ever-tougher fights.

Both foundation hospitals and top-up fees have seen him giving so much ground that he must wonder whether all the pain is worth so little apparent gain.

As the election nears, he will have to draw closer to his MPs and his party. That's if they still want to draw closer to him.