Pressure on senior Cabinet ministers to tell Gordon: It's time to go

The Cabinet will be urged to ask Gordon Brown to stand down if Labour's ratings continue to flatline after the party conference season, it emerged today.

Amid reports that the Prime Minister has been thumping the table with frustration at his poor poll ratings, his critics have decided that it is up to senior ministers to step in to prevent a messy leadership challenge.

Friends of former home secretary Charles Clarke have reportedly persuaded him not to launch a challenge this autumn, preferring Cabinet  'greybeards' such as Jack Straw, Geoff Hoon or Alistair Darling to tell Mr Brown his time is up.

Labour MPs have talked about 'excruciating' Downing Street meetings with the Prime Minister in recent weeks, during which he was challenged on his claim that he was the best person to lead Britain through economic bad times.

They fear that a defeat in the Glasgow East by-election, coming on top of the Crewe by-election defeat and the loss of London to Boris Johnson, could prove terminal for Labour's chances of recovery in time for the general election.

One minister told The Guardian: "The big moment will come after the Conservative conference. If the Tories are 20 per cent ahead, then there will be movement."

Last night it was revealed the Prime Minister was confronted with growing complaints about his leadership when he summoned MPs to private talks about his future.

Mr Brown was asked by anxious backbenchers what he was doing to counter public doubts about his fitness to be Premier at a meeting in Downing Street.

In reply, a frustrated Mr Brown 'thumped the table' in the Cabinet room and urged his MPs to tell voters about the Government's record on health and education.

But when he tried to blame Labour's difficulties on the global economics crisis, a former minister told him: 'Many say you are the problem. What are you going to do about it?'

The account of the rising tensions between Mr Brown and his MPs emerged amid growing speculation that he now faces an inevitable leadership challenge.

He has launched a behind-the-scenes campaign to head off attempts to topple him this summer by inviting groups of MPs to meet him in Number 10.

Backbenchers from different regions in groups of about a dozen at a time have been asked to give their assessment of the challenges facing the party.

Each has been invited to voice his concerns, prompting some to speak candidly about fears that the party is in trouble.

They have emerged to describe 'excruciating' exchanges in which Mr Brown refuses to acknowledge his part in the Government's disastrous ratings. 'It was painful to watch,' one MP said.

'He claimed it was all down to the global downturn, and thumped the table as he told us to tell voters about Labour's achievements.

Mr Brown insists in public he is the only one who can lead Labour out of the political black hole it finds itself in.

Speaking from the G8 summit in Japan yesterday, he made clear he has no attention of standing down.

September is emerging as a decisive month that could see growing frustrations about his performance boil over into a challenge.

But his allies are urging him to take pre-emptive measures including reaching out to MPs and an autumn reshuffle.