Michael Howard mocked Tony Blair's U-turn over the European constitution referendum yesterday, saying: "Who will ever trust him again?"
Tory MPs cheered as the Conservative leader attacked during a historic statement announcing the national poll on the proposed EU constitutional treaty.
Mr Howard said: "Six months ago the Prime Minister stood before his party conference and told them with all the lip-quivering intensity for which he has become famous: 'I can only go one way. I've not got a reverse gear.' Today you could hear the gears grinding as he came before usto eat all those words which he has pronounced so emphatically for so long. Who will trust him again?"
Mr Howard lambasted Labour MPs for voting down Tory proposals for a referendum last month. He said: "There they all sit. Marched up to the top of the hill by the Prime Minister to oppose a referendum just three weeks ago, then marched down again; the loyal foot soldiers of the Grand Old Duke of Spin."
Charles Kennedy, the Liberal Democrat leader, urged the Prime Minister to set up a pro-European campaign crossing all political parties, warning: "The quicker pro-European forces are able to co-ordinate and to make the positive case based on the facts, the better. This is a historic opportunity to settle an issue that has bedevilled two generations of British politics and each of every successive government, of whatever political persuasion."
MPs across the Commons demanded to know the reasons behind Mr Blair's change of heart after he repeatedly ruled out a poll. Donald Anderson, the Labour chairman of the Commons Foreign Affairs Committee, said: "My right honourable friend made a powerful and convincing case over the past year that there was no need for a referendum and there is every reason to think that by the end of June there will be something of a triumph for British diplomacy and our red lines are maintained. So he will not be surprised if some of us ask what is the new factor which has occurred?"
Mr Blair replied: "What we have to accept I'm afraid is however much we may disdain the position taken by the party opposite ... the fact of the matter is that this argument is not yet won in the country."
Frank Field, a former social security minister, urged Mr Blair to hold a referendum before the next election. He said: "Could I thank the Prime Minister on behalf of Labour voters who have longed to hear him make the statement he has made today."
David Curry, a former Conservative environment minister, asked: "Don't you remember taunting a previous holder of your office with weakness over his party and his government concerning Europe? Are you not in exactly the same position? Given the abandonment of everything you have ever said about the constitution, all of course with characteristic biblical certainty, does that description not now rightly apply to you: weak, weak, weak?"
Ian Taylor, pro-European Conservative MP for Esher and Walton, said: "The Prime Minister has done a handstand so that the sun can shine out of part of his anatomy."
Mr Blair replied: "It is the right moment for those of us in the Conservative Party, as well as on these benches, who believe passionately that Britain's place is at the centre of Europe decision-making, to make our case."