With the Commons returning from its Easter break on Wednesday, ministers face a number of make-or-break votes on the European Communities (Amendment) Bill in the next month.
But the President of the Board of Trade raised the stakes yesterday when he said that John Major would be finished if he dropped the treaty, and it would be 'crazy' to throw away the advantage of the Social Chapter opt-out.
Mr Major's critics have already begun a whispering campaign against him, threatening a destabilising leadership contest when the new session of Parliament opens in November.
But Mr Heseltine told BBC radio's World this Weekend that if the Prime Minister deferred to the demands of the rebels and dumped the treaty, 'the effect upon the credibility of the man would be profound. I think he would believe that he had put his commitment, put his name, put his reputation, and with very great success achieved the concessions he did at Maastricht, and then would be seen to have backed away.
'He would believe, as I judge the man, that when he next spoke to his peers in Europe, they would all be looking at him, saying: 'Yes, this is the guy who signed up before, and ran away.' That is not the sort of prime minister we've got and that is not the sort of man I judge John Major to be.'
George Robertson, Labour's frontbench spokesman on Europe, said that he expected a vote on New Clause 75 - which could block ratification of the treaty with Mr Major's Social Chapter opt-out - within the next three weeks.
He said that if the Government was defeated, the Tory rebels believed Mr Major would not sign up to the Social Chapter, 'and would rather walk away from the treaty with all the implications that would have' . He went on: 'We believe that Mr Major could easily sign up to the Social Chapter, since all the other 11 governments believe it's quite sensible and practical to do so, and that he would do so rather than face the opprobrium of destroying the treaty for the whole 12 countries of the Community.'
James Cran, one of the Tory rebels' unofficial whips, said: 'If we find that there's a way, by voting for this, that, or the next amendment, which will kill the treaty, I think my colleagues and myself will be sorely tempted. We haven't come all this way, we haven't had the kitchen sink flung at us continuously, just to chicken out now.'
Mr Heseltine said: 'If somebody in the Conservative Party is saying that they're prepared to play games with the tactics, the risk of which is to bring back the Social Chapter, I find that extremely disquieting.'
He added: 'We're trying to bring this country through a very difficult recession. We're trying to seek British self-interest at the heart of Europe. We have a programme for a Parliament and we will not be blown off course. There may be some squalls, there have been a very rough series of patches in the last 12 months, but in my view there are now real signs that things are getting better.
'And I have no doubt whatsoever that the British people will respect the Prime Minister for the judgement that he's shown and the nerve that he's kept when they have to make a judgement about his performance.'Reuse content