Blair, on the final leg of his fight on Sunday offered new concession to rebels likely to oppose his education policy in a make-or-break vote.

The Tuesday vote and judge Lord Hutton’s report into the death of government scientist David Kelly pose a huge threat to the Prime Minister’s authority – already under strain after the failure to find weapons of mass destruction in Iraq.

Asked by Sunday's Observer newspaper if he would still be leading the country by the end of the week, Blair said: "I have every intention of doing that, yes."

But defeat over plans to allow universities to charge students more for their education through "top-up" fees would be humiliating for a prime minister with a massive parliamentary majority and could trigger a confidence vote.

Last-ditch concession

In a sign the battle with Labour rebels was still raging, Education Secretary Charles Clarke said on Sunday the education bill would now carry a guarantee the upper threshold for fees would not rise above £3,000 ($5,526) for two general elections.

"I think we will win the vote on Tuesday but there is certainly a hill to climb," Clarke told BBC television.

The Labour rebellion comes on the back of an erosion in Blair's popularity and public trust ratings after his decision to back the US-led war on Iraq on the basis its lethal weapons posed a threat.

Most political analysts believe Blair will survive this week, but the row over Iraq's weapons - a key Anglo-American justification for war - shows no sign of abating.

That issue could prove more decisive than this week's events in shaping the political landscape ahead of the next general election, expected in 2005.