A Cabinet minister told colleagues yesterday to avoid the impression of “jostling” to succeed Gordon Brown as the Prime Minister prepared to reenter the political fray.

Andy Burnham, the Culture Secretary, helped Mr Brown’s relaunch prospects by saying that, at a testing time for Labour and the Government, they should avoid a “period of introspection”.

His intervention came as Mr Brown’s troubles mounted, with a veteran Labour MP suggesting that Mr Brown was in the “last chance saloon” and a poll indicated that voters would overwhelmingly prefer to have David Cameron as prime minister.

Speaking on Westminster Hour on Radio 4, Mr Burnham delivered a thinly veiled warning to the supporters of David Miliband, the Foreign Secretary. He said that Labour must come up with a policy programme that reflected the pressures people were facing.

He then added: “It is in our own hands as to how we respond and I have every confidence that we will respond in the right way. The right way is not appearing that we are obsessed with ourselves and our own positions and are constantly jostling and manoeuvring about those kind of things, and are instead talking about the things that matter to people because they are feeling them directly.”

Mr Burnham’s remarks are important because he is from Mr Miliband’s Blairite wing of the party. They come amid apprehension in the Brown camp that his critics are about to launch a late summer offensive to destabilise him.

Mr Brown was back at the helm yesterday although he will not return to London until today. He will fly to Beijing tomorrow for the final days of the Olympic Games. Downing Street said yesterday: “The Prime Minister is in charge and he is performing that task this week. When he goes to China, Jack Straw will be the minister coordinating government business.”

As The Times reported yesterday, Mr Brown’s reshuffle could be delayed until October. When asked about the job prospects of Ivan Lewis, the Health Minister, who on Sunday controversially called for higher taxes on top-earners, a Downing Street spokesman said pointedly: “He is doing an excellent job at the Department of Health.”

An ICM poll for The Guardian today has Labour lagging 15 per cent behind the Tories, on 29 per cent to 44 per cent, with the Liberal Democrats on 19 per cent. If the results were repeated at a general election they would translate into a 100-seat majority for Mr Cameron. Mr Brown’s personal ratings were even worse, with 21 per cent saying they would choose him as Prime Minister, compared with 42 per cent for the Tory leader. Mr Cameron was the choice in every age bracket, social class and part of Britain except Scotland. The silver lining for the Prime Minister was that Mr Miliband fared no better as a potential leader, also being preferred by 21 per cent.

The Labour MP Austin Mitchell said that his party was stumbling towards defeat. “We already display too many of the symptoms of a government at the end of its tether: the bickering, the declining enthusiasm, the shuffling positioning and repositioning of leadership contenders, along with escapist dreams about a period in opposition in order to get our heads straight,” he wrote on the Compass website.

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