The Government is beginning to win the argument with its MPs on top-up fees

There are moments in the ebb and flow of political forces that can be identified as turning points. When it comes to university fees, it's just possible that yesterday's electrifying meeting of the Parliamentary Labour Party will turn out to have been one of them. The doubtlessly well-organised presence of its supporters - Cabinet ministers very much included - at a better than usually attended meeting helped the Government, of course. But it couldn't wholly explain the sense among at least some of the PLP's most seasoned participants that the argument was slowly and painfully moving in the Government's direction.

If anyone has good grounds to be fed up with Tony Blair, it's Tony Banks. It's not that he's one of the dangerously dispossessed and growing army of former ministers in Labour's ranks. As Banks never fails to point out, he jumped rather than was pushed. Rather it's that he has more reason than most to quarrel with the deeply unprincipled fix by which the Prime Minister has just brought Banks' old rival Ken Livingstone back into the Labour Party. Yet here was Banks yesterday denouncing in characteristically fruity terms those of his fellow ex-ministers who used to have their noses "pushed firmly up the Prime Minister's backside" and are now using the row over top-up fees in an effort to see him off.

Banks has always combined an independent outspokenness with a larger party loyalty, of course. But his remarks on the Today programme set the tone for what followed later in the morning. The numbers of those who spoke at the PLP debate - 18 in favour compared with five against - is much less significant than what they said. Across a fairly broad spectrum of party opinion, several MPs - Janet Anderson, Andrew Miller, Kevin Barron (a recent convert to the cause of top-up fees) among them - turned on the ex-whips among those leading the rebellion in tones rarely heard at such a meeting since the bad old days of the 1980s.

Amid the calls to renounce "personal issues of ambition" and a strategy which would mean the "only winners would be the Tories" there were pointed questions: why, it was asked, were those who as whips had used all their skills to force through a deeply unpopular policy of up-front tuition fees in the first Blair term now working to undermine a policy which - among many other things - would end up-front fees in favour of a gradual system of repayment?

There is precious little evidence as yet of large-scale defections from the fatal 100-plus rebels claimed by the dissidents' leaders. It's therefore a good deal too early to predict with any confidence that yesterday will be a turning point. But if it is, it will be, I think, for two reasons. The first is a certain unease within the PLP caused by the perception - emphatically and repeatedly denied by the men themselves - that two of the rebellion's ring leaders, the former chief whip Nick Brown and his then deputy George Mudie are seeking to engineer a Commons defeat for its own sake, and the damage it would do to Tony Blair's authority. This may have been helped by the (no-doubt calculated and pro-Government) leak of a note from Mudie identifying wavering MPs to be persuaded before the all-important second reading vote on 27 January (though, equally, the leak itself may have been a tactic which will harden the hearts of some rebels.)

Now this isn't to deny that there is at the very least a hard core of MPs who would enthusiastically cheer if Blair were fatally damaged by a Commons defeat on fees. And for whom every Prime Ministerial declaration that his authority is on the line is an invitation to vote against him rather than for him. And even if that wasn't the case, there is nothing unprecedented about this kind of unofficial whipping. It's what ex-whips do best. Even the dark and so far unsubstantiated ministerial accusations that rebel leaders are working in concert with opposition forces aren't new. It's exactly what happened in the Maastricht rebellions in John Major's time. But that's rather the point. The Maastricht revolts didn't - in the end - bring John Major down. But by exposing the depth of divisions within Conservatism, they played a mighty part in ensuring his government's defeat at the next general election.

The second factor, however, has to do with the policy itself. And on this, there are real signs that Blair and Charles Clarke (not least in their speeches yesterday) are beginning to win the argument if not yet the vote. In particular, they are beginning to dispel the notion that, coupled as it is with a big increase in help for the poorest students, the policy would narrow rather than, as it will, actually widen access to university. If anything this is a hit - and an overdue one - on prosperous middle-class parents for whom free higher education has long been a perk that has soaked up much of the funds that ought to be deployed on state provision from the cradle to school-leaving age. If it were so deployed there would be wider distribution by social class of those getting the A-levels they need to get to university in the first place. Which makes it an even neater irony that the rebellion is being led by politicians of the old Labour right against those like Clarke whose roots are in the soft left of the party.

Yes, it should have been foreshadowed in the manifesto; and it probably would have been if the Government had thought through the problem more deeply before the review of tuition fees it carried out after the last election. But the fact that it won't be implemented until after the next election is a real-world point that goes a long way to meeting this complaint. It will be put to the electorate at a time when it can easily be reversed by an alternative government if it chooses to do so. But if legislation had been put off until after the next election, it's a fair argument that the university preparations needed would have meant implementation not much earlier than 2009, by which time the universities' international competitive edge would have been eroded all the more.

There are other straws in the wind. The Chancellor will be crucial in the next fortnight, and not only because the likes of Nick Brown, Mudie, Clare Short and others would certainly prefer him as PM. Brown, who long had doubts about the timing, is said to remain deeply irritated that the row over variable fees has been allowed to develop into a "high noon" for Blair, and at what he sees as some of the more divisive tactics being deployed in support of the policy. If nothing else, however, he was at his most unequivocal yet yesterday in calling for support of the Government's measure

There is nevertheless a whole lot more work to do. It isn't surprising that Blair will be devoting a big part of every day to winning the case. If he gets through Hutton and wins on this, there is nothing anything like as momentous to confront him between now and the next election. If he fails, the damage to his authority will be incalculable. If I had to predict, it would be that the policy will scrape through, as on its merits it certainly should. But it remains a very close call indeed.

d.macintyre@independent.co.uk