Revealed: new plot to oust Blair

* Ultimatum to PM issued by MPs loyal to Brown<br/>* Email conspiracy uncovered by the 'IoS'<br/>* Hain stakes claim to be new deputy leader

Tony Blair's efforts to cling to what remains of his leadership are dealt a heavy blow today as another plot to oust him is exposed.

A letter signed by at least 10 Labour MPs elected at the last election calling on the Prime Minister to quit immediately has been obtained by The Independent on Sunday. The letter was due to be made public on Friday, but was held back in the wake of Mr Blair's public statement that he would be gone in a year.

One of the signatories has told this newspaper that it could still be delivered. "If we aren't happy at the way the hand-over is going, we will send it in," said the MP. A senior Downing Street figure dismissed the new MPs' threat as an inept attempt at blackmail, however.

Gordon Brown, meanwhile, will today move to refute claims by the former Home Secretary Charles Clarke that he is a "control freak" who cannot work with colleagues. The Chancellor has been the target of a wounding backlash in the wake of the Prime Minister's coerced public declaration that he will quit within a year. Downing Street privately believes he was behind a letter signed by 15 MPs elected in 2001 calling on Mr Blair to quit.

It was that letter, and the subsequent resignation of eight junior members of the Government, that forced Mr Blair to make his statement. It emerged last night that Mr Brown met one of the signatories, Tom Watson, last weekend at his home in Fife, Scotland. The defence minister, who quit last week, has denied that he discussed his intentions with Mr Brown.

But suspicions of a plot will be further fuelled by a leaked email to Helen Goodman, Labour MP for Bishop Auckland. It makes clear that she was involved in collecting signatures for a second letter, this time signed by MPs elected in 2005. "Very frustrated at lack of phone connection. Perhaps we can converse in code through Parliamentary e-mail system," reads the email from a "citizenpaine".

It also contains the text of a letter to Mr Blair that concludes: "The belief there should be an urgent change of leader and Prime Minister is shared widely among colleagues in the Parliamentary Party and members of the Labour Party."

Ms Goodman said simply: "No letter was sent by the 2005 intake to Downing Street." She made clear her own allegiances by contrasting her own "responsible" behaviour with that of the senior minister quoted by the BBC as saying Mr Brown would be an "effing disaster" as PM.

Meanwhile, Peter Hain is preparing to launch his bid to become Labour deputy leader. In an interview in this newspaper, the Northern Ireland and Wales Secretary attacks Alan Johnson, regarded as the front-runner for the position, who declared his candidacy last July.

He said the question of who should replace John Prescott arose when the Deputy PM "was at his very lowest". "I thought it very disloyal to be trying to grab his job. At the time when others were declaring ­ and that's a matter for them ­ we had no idea of how far off a contest would be. I felt it highly premature and disloyal.

"Whoever is our next deputy leader should be someone who doesn't have one eye on the top job. We don't need another period of mistrust and division at the top." Although both Mr Blair and Mr Brown issued calls for calm there seems little chance of an end to the in-fighting. The Prime Minister is reported to have told one close friend: "I have never known how mendacious [Brown] was, how full of mendacity." Ten Cabinet ministers are reported to be preparing to back an alternative "New Labour" candidate in the leadership election.