Tony Blair's flagship Education Bill finally cleared the Commons last night with Tory support despite a fall in the Labour backbench rebellion.
The Education and Inspection Bill passed its third reading in the Commons by 422 votes to just 98.
The rebellion by Labour MPs fell to 46, a figure well down on Tuesday's symbolic rebellion by 69 backbenchers, but still leaving the Government reliant on Conservative support.
John McDonnell MP, chairman of the Socialist Campaign Group of MPs said it was "a very significant rebellion". He said: "On a succession of votes tonight on this Bill the Government's majority has collapsed and it has only been pushed through because of Tory party support.
"We are alienating not just large numbers of Labour MPs, but wide sections of the party and our supporters, to whom our commitment to comprehensive education is absolutely central."
But Government sources expressed satisfaction that rebel numbers had fallen.
Alan Johnson, the Secretary of State for Education, signalled that the rebellion had reduced as the vote was announced in a packed House of Commons last night.
Speaking at the end of two days of detailed debate on the Bill, Mr Johnson urged MPs not to vote against the legislation.
He praised the "mature debates" on the Bill, telling MPs: "The Government has listened very carefully and responded where possible to make this a better Bill ... The Bill focuses on unleashing the potential of very child. With nine years of successful experience of raising the educational attainment of every child we can build on what works well."
He added: "What educational advantage would result from the defeat of this Bill? It's a bill that will drive up educational standards."
David Willetts, the shadow education secretary, pledged support for the measure, but mocked Mr Blair for giving in to his backbenchers. He said: "We will use the powers in this Bill to make sure it is easier for schools to expand. We will use the powers in this bill to give more freedom to schools."
But Sarah Teather, the Liberal Democrat education spokeswoman, attacked the "love in" between Labour and the Conservatives over the legislation. She said: "We think this bill is a missed opportunity. It is a timid Bill with hidden dangers and for that reason we will not be voting for it."
The Bill, which now goes to the House of Lords, makes it easier for parents, and voluntary and church groups to open new schools by setting up a contentious new system of self-governing "trusts" with greater control over their own affairs.
But it has encountered bitter opposition from a coalition of Labour MPs.
Earlier this year Mr Blair admitted that the passage of the legislation would be a "high-wire act".
Earlier yesterday Labour rebels staged an attempt to abolish the 164 remaining grammar schools in England, as the Tories completed a U-turn on selection.
David Chaytor, Labour MP for Bury North, tabled an amendment to the Bill demanding that all academic selection be abolished by 2010. He said the remaining grammars were "an anomaly".
Nick Gibb, for the Conservatives, admitted that the selection scheme was "socially divisive", and called for all schools to offer grammar-style classes by grouping children by ability. But he said the Tories would retain the existing grammar schools.
He said: "If you set within a school flexibly, but comprehensively, then you don't need to have all the upheaval that would be involved in going back to selection.
"What we do need to do is to make sure that in many of our comprehensive schools we have a much more enhanced and accelerated curriculum that really does stretch the brightest children."