Cabinet colleagues tried to shore up Tony Blair's position yesterday after Deputy Prime Minister John Prescott fuelled speculation about his leader's future.

Senior ministers were jockeying for position in anticipation of the Prime Minister stepping down, Mr Prescott said.

His disclosure was followed by reports that he had held secret talks on a "peaceful succession" with Chancellor Gordon Brown.

That was dismissed by a spokesman for Mr Brown, who said the pair simply shared a car following a memorial service for former Labour leader John Smith last Sunday.

However, there were other reports that the Chancellor was preparing to take charge amid questions over Mr Blair's intentions and continuing problems in Iraq.

Labour officials have publicly agreed with a poll suggesting the PM has become an electoral liability.

And as Mr Blair faces fresh unrest from his MPs over sending more troops to Iraq, leaked private polling for Labour was said to have reached the same conclusion.

Despite these blows, he will stay on at least until elections are held in Iraq next January, an anonymous friend told The Observer.

That was backed up by Defence Secretary Geoff Hoon who said on Iraq, the premier was "absolutely determined to see this job through".

He was among Cabinet ministers who paid tribute to Mr Blair and stressed he should stay in charge.

"Here is a man focused, engaged on the job, determined to sort out Iraq and allow Iraq to become part of the international community again," Mr Hoon said.

Commons leader Peter Hain warned it would be "crazy to just duck for cover and panic and run around in a frenzy".

Mr Hain said he had met the Prime Minister privately last week and "he is absolutely determined to continue discharging the responsibilities of his office".

Foreign Secretary Jack Straw, said to have forged an alliance with Mr Brown in recent months, said: "There are difficulties. But people misunderstand our Prime Minister Tony Blair if they somehow think he is going to run away from his responsibilities because there is a lot of speculation in the newspapers."

In Mr Blair's Sedgefield constituency, his agent, John Burton, last night insisted the Prime Minister was as committed as ever and that "he is the only man for the job".

He said: "He is not considering resigning, his thoughts for the future are about taking the party forward to the next General Election.

"People who are thinking about the next election should remember that previous Prime Ministers have been well behind in points and polls but gone on to win - Margaret Thatcher was 20 or 30 points behind Neil Kinnock when she came to power.

"Labour has more chance with Tony Blair than with anyone else, he is the best man for the job."