Labour MPs fret as Cameron taunts Blair over 'paralysis' in the government

Tony Blair's hopes of remaining in Downing Street until next summer suffered a setback yesterday when he was taunted by David Cameron at Prime Minister's Questions.

A rattled Mr Blair was thrown on to the defensive when the Tory leader attacked the "paralysis" in the Government caused by the Prime Minister's long departure timetable. With Gordon Brown next to him, Mr Blair twice declined to endorse the Chancellor as his preferred successor.

Mr Blair's lacklustre performance in his first weekly joust with Mr Cameron since announcing he would quit by next autumn reopened the debate among Labour MPs about how long he should stay on. It ended the euphoria over Mr Blair's speech to last month's Labour conference, which appeared to buy him the space to leave in his own time.

Labour MPs said last night that the Prime Minister's grip on power was slipping away and urged him to quit sooner rather than later. Shop stewards representing Labour MPs, who met Mr Blair after Prime Minister's Questions, were dismayed at his performance. One said: "People have tried to push him out and that failed. Gordon can't lift a finger now. But Tony cannot go on like this." Ian Gibson, a long-standing backbench critic of the Prime Minister, said: "The head is off, but the legs are still kicking." He called on Mr Blair publicly to endorse Mr Brown.

Glenda Jackson, a former government minister, said: "This is a burden he has placed on his own shoulders and the pressure will increase until he finds the courage to give a date for his departure. The sooner he does that the better."

One senior Labour MP said: "It was the worst performance that I have seen by Tony. He let Gordon down. People are now asking how can Tony go on. We needed to see that his heart and his head need to be fully engaged. But his heart isn't in it any more. He should go."

A former Labour minister said: "He's got to say he is going next February, and a new leader will take over next May."

Even Blair loyalists were appalled at his performance. "I've never seen him fumble the ball like he did today," said one ally. "I don't know how long he stay on after this."

There was no sign of ministerial resignations to force the Prime Minister to step down immediately.

MPs close to Mr Brown predicted that Mr Blair would bounce back, but said he had been ill-prepared for Mr Cameron's onslaught. "We can't have this every week," one said.

The Conservative leader argued that problems such as overcrowded prisons and the financial crisis in the NHS were being made worse by the continuing uncertainty over Mr Blair's future. He asked the Prime Minister: "Do you back the Chancellor as your successor, yes or no? I mean, I do." Mr Blair said he did not resile from his previous remarks that he would be happy to see Mr Brown take over, but he refused to be drawn further on the issue, insisting that he wanted to talk about policy.

Some Labour MPs are anxious that Mr Blair's authority is draining away so quickly that Labour will be severely damaged before a new leader is in place. They see the next session of Parliament, beginning on 15 November, as a dangerous time for Mr Blair. Many MPs will be asking how he can introduce a Queen's Speech when he will not be staying on to see it through.

Conservative MPs were jubilant at his failure to rise to the challenge thrown down by Mr Cameron. "How long will it before Cameron tells him: In God's name - Go?" said one former Tory minister.