Tony Blair has told his party he wants his school reforms to get through the Commons in a Labour Bill - signalling he hopes not to rely on Tory support.
Tony Blair, left, with Education Secretary Ruth Kelly
He told MPs it was important to take tough decisions at the start of the third term in office, to pave the way for a fourth term in power.
"I want this bill as a Labour bill," he told the parliamentary Labour party.
Mr Blair has been courting up to 100 Labour rebels, who fear the bill will allow good schools to select pupils.
'Listened and responded'
The prime minister's spokesman said Mr Blair told the gathering: "This period can be a defining moment for us," which would cement the party's "rhythm of government".
He said ministers had listened and responded to the concerns of Labour MPs on the education reforms.
Labour critics have feared the bill could set up a two-tier education system by allowing schools to pick the best students to help improve their exam pass rates.
Under the plans, private companies, faith groups and parents, will be given freedom to set up and run schools under the state system.
It will also allow existing schools the freedom to develop "partnerships" with outside organisations and establish "federations" with neighbouring secondary schools.
Without the support of most Labour MPs, the government would have been forced to depend on the support of Tory MPs.
But Barry Sheerman, chairman of the Commons education committee, told BBC News 24 he was now "absolutely sure" Labour MPs would fall behind the proposals.
"People have been consulted - they have seen that the government has moved," he said.
"This is not a watered down bill. It's a much tightened up, improved bill - lots of guarantees have been given that were wanted."
Ex-Cabinet minister David Blunkett said he also did not think the government would need the votes of Tory MPs to win the vote on 15 March.
He told Channel 4 News: "Although this is a difficult issue, although of course people feel very strongly about it, I don't think we should at this stage - over two weeks before the vote on March 15 - actually get engaged in that kind of personalisation."
Earlier, Mr Blair said the "furore" over the reforms will be forgotten once they are implemented.
It was time to build on the "massive" investments ministers have put into public services and push up standards throughout the system, he said.
"Very often when we have been faced with difficult reform, we have had controversy, but when we persisted and got the reform, we have reaped the benefit of it. It will be the same again," he said.
He said the government had to "continue with change" while there were significant numbers of young people not getting the education they need.
"For me this is absolutely the crux of what a Labour Government is about," he said.
The bill is now expected to outline a ban on interviewing children and their parents.
Education Secretary Ruth Kelly said she would retain the right to veto councils' attempts to set up comprehensives under the new legislation.
However, relinquishing the veto is one of the key demands of the rebels who are threatening to vote against the prime minister over the bill.
Despite her refusal to back down, Ms Kelly said she believed most Labour MPs would accept the proposals would be good for children and give them their backing.
That strategy was tempered by a £30m "carrot" for local authorities to spend on failing schools.
Shadow education secretary David Willetts said his party would try to restore some of the bill's "original radicalism" as it went through the Commons.
He said he regretted the concessions to date, but pledged that it was even "a step in the right direction", the Tories would support it.
Ed Davey, the Liberal Democrats' education spokesman, described the £30m promise as a "desperate" measure to appease rebels.