Blair suffered his first major defeat as prime minister earlier this month over anti-terrorism plans when nearly 50 lawmakers in his Labour Party -- about one in seven -- refused to support him.

The shock vote raised questions about Blair's grip on his party after Labour's majority shrank in a May election.

Defeat in the education vote in the first half of 2006 would seriously dent his authority and could increase calls for him to step down after he said he would not seek a fourth term in a general election to be held by 2010.

Amid reports that at least one senior minister voiced opposition to the plans at a meeting last week, Geoff Hoon, a cabinet minister and close political ally of Blair, acknowledged the government may alter them to avert defeat.

"This is a process. It doesn't just change as a result of a single meeting. There are a lot of discussions that will take place, both within the cabinet, in cabinet committees and with members of parliament (MPs)," Hoon told BBC Television.

"Out of that discussion I believe there will come adjustments, but the central thrust of what we are doing I believe is right," he added.

IMPATIENT

Blair has kept iron control on Labour up to now because of his ability to win elections -- three in a row.

But having said he will not fight another one, that card can no longer be played and many Labour MPs are impatient for Chancellor Gordon Brown to take over.

Hoon said Brown was the "overwhelming choice" of the great majority of Labour members to take over from Blair without a contest, but said a selection process would be needed if another candidate "with appropriate support" chose to stand.

Critics of the education reforms say they would pit schools against each other and bring back selection by ability, creating elitist institutions and benefiting the middle classes most.

Some 28 Labour MPs have signed a motion opposing the plans to give heads and parents more power on admissions and teaching.

Since Blair's majority was slashed in May, it takes fewer than 40 Labour MPs to vote with the opposition to defeat him.

Aside from education, Blair also faces Labour opposition to plans for national identity cards, to cut disability benefits and on more private sector involvement in the health service.

Hoon said there had been a "lively" debate in cabinet last week on education -- an issue that "stirs passions".

"We've got to recognise that a smaller majority means there has to be a great deal more discussion, persuasion," he said, but added: "I do believe we can get those changes through."