Gordon Brown has ordered his supporters to maintain their discipline and unity amid mounting reports that Tony Blair is set to quit before the next election.

A number of Cabinet ministers used media interviews yesterday to defend the prime minister.

Foreign secretary Jack Straw declared that Blair was not about to "run away" from responsibility.

A spokesman for Brown, who is running his party's campaign for the June 10 elections, said: "This kind of silly gossip is without foundation and nobody who is really a friend of the chancellor would have indulged in such nonsense."

He added: "This is a time for discipline and unity. Surely by now people should have learnt that our dividing lines should be with the Conservatives and not within the Labour Party."

According to newspaper reports, John Prescott met with Brown in a secret meeting held in the back of a ministerial Jaguar in Scotland last weekend.

The two senior Labour figures, who were attending a memorial service for the late party leader John Smith, are reported to have discussed plans for the succession in the car park of the Loch Fyne Oyster Bar.

"They were at the same event and unsurprisingly they shared a car. That's perfectly normal," insisted a spokesman. 

Interviewed in the Independent, education secretary Charles Clarke describes reports of the prime minister quitting as "nonsense".