You are either for it or against it. So you are either for him or against him

The stakes are high. The speculation is intense. Charles Clarke, the Secretary of State for Education, has cleared his diary to put the case for top-up fees. The Prime Minister is on call to do the same. He has hinted he will resign if he loses the Commons vote next month. It does not get much bigger than this. The Government has to win. Yet the rebels insist they must not lose. Surely there has to be a way through?

The proposal to introduce top-up fees for universities has a single common link with the poll tax, the policy that helped to bring about the fall of Margaret Thatcher. The policy defied amendment. You were either for the tax or against it. Mrs Thatcher, who used her reverse gear almost as frequently as Mr Blair, made a series of changes to the original proposals in an attempt to make them more politically acceptable. In doing she changed the entire policy without making it more popular. Many of those on low incomes received massive rebates when the original plan was that nearly all voters should pay the same amount. In another u-turn the government imposed caps on councils that set high poll tax bills. By the time she had been booted out of power the poll tax had ceased to be the poll tax at all. All the principles had been thrown out of the window.

Variable top-up fees for universities are also beyond amendment. You are either for them or against them. Again the policy is very simple. Students borrow an interest-free loan and repay it when they are earning a decent salary. Within clearly defined limits universities are able to vary their fees. Already ministers are making the situation more complicated. They point out that those from poorer backgrounds will get bursaries from the richer universities. Perhaps these students will not have to pay anything at all. This distorts a central principle behind the proposal, which is that students should repay the loan on the basis of their earnings after graduation, not because of their background before they went to university. Concessions tend to produce convoluted anomalies. It is likely now that a graduate from a poor background could earn a fortune and not pay a top-up fee while a graduate on a low income will be repaying the loan. If more concessions are made the Government will fail to raise anything like the additional revenue it requires to address the decades of under-funding while increasing substantially the number of teenagers who go to universities. Yet beyond throwing money at the policy to the point where it becomes meaningless there is little the Government can do about the concerns of some Labour MPs.

The impossibility of amending the policy in a way that does not destroy it is the only link with the poll tax. Mrs Thatcher's flagship was a monster of a policy, out of control from the beginning with some families on low incomes suddenly facing bills amounting to thousands of pounds. The top-up fee is a relatively minor reform. Some of the Government's education policies that target the under-fives are much more significant. As far as top-up fees are concerned the loans are generous, the repayments will be made only when people can afford them and the measure is in addition to a significant increase in public spending on universities. So why has the issue become so highly charged?

The answer is that Tony Blair has decided to make it so. The Prime Minister finds himself in the middle of another storm. Yet again he calls on his reluctant and restive followers to head in his direction. He has no reverse gear. His subliminal message is starker. If his weak-kneed supporters do not follow him to the Promised Land they will be swept away by the tempest. The future of the Government and the Labour Party are at stake. What an apocalyptic scenario - and all over the financing of universities.

Like Prospero in Shakespeare's The Tempest, Tony Blair is always creating storms, seeking to manipulate those who get caught up in them. Quite simply, we have been here too many times before. The magic becomes less convincing. Each month at his Downing Street press conference Mr Blair is seen railing against his own side, urging it implicitly to grow up and adapt to the modern world. Last week top-up fees became the latest do-or-die issue, of such historic importance that a prime ministerial resignation is possible if he does not get his way. A few months ago foundation hospitals were the crucial test of whether Mr Blair's party had entered the 21st century. Before that support for the war against Iraq was the issue over which he staked his premiership. For the Prime Minister, a tempest is never far away.

The thunderous confrontations, though, have strict limits. Most prime ministers ally themselves with their parties in an attempt to change the country. Obsessively, Mr Blair prefers to be seen taking on his party in order to bring about relatively modest changes. He is much more reluctant to adopt a high profile over arguably more important policies that would involve him challenging those outside his party. A modern transport system is as important to the economy and our quality of life as some additional cash for the universities. He does not crusade over congestion charges and motorway tolls. He does not dare even to give his views on these policies. In the summer Mr Blair promised to stage some euro roadshows. He has applied his reverse gear and dropped the idea. On the thorny issue of tax the Prime Minister keeps his head down. These are issues that would require him to persuade Middle England, motorists, taxpayers, Euro-sceptic newspapers and the mighty establishment of the need to move in a new direction. He is happier taking on his party. On some issues he has been right to do so. But the persistent positioning, in which he places himself as the crusading and bold moderniser leading a backward-looking party, is stretching the loyalty of Labour MPs, especially when he is so timid on other issues.

This is the significant development. Labour MPs are stirring. An astonishingly large number of them voted against his decision to go to war and many more wished they had done so. They resent being told once more that the future of the country is at stake over another policy. There are echoes here with the dying days of Mrs Thatcher. In October 1990, she was cheered to the rafters at the Conservative Party conference. She returned to Westminster and discovered that her MPs were turning away. Mr Blair was received ecstatically at Labour's conference. A significant number of MPs are becoming much warier. Now the leader and his parliamentary party are confronting each other over a policy that cannot be finessed to satisfy both sides. One of them will have to lose.