PRIME Minister Tony Blair was last night facing demands for his resignation amid mounting pressure from all sides.

Former Cabinet minister Clare Short called for him to quit for his handling of the Iraqi crisis, while speakers at the annual Durham Miners' Gala branded his New Labour project "an abject failure".

Further pressure was heaped on Mr Blair by the former United Nations chief weapons inspector, Dr Hans Blix, who accused him of making a "fundamental mistake" in his interpretation of the intelligence dossiers which led to the war in Iraq.

Dr Blix said Mr Blair was wrong to declare Saddam Hussein could deploy weapons of mass destruction in 45 minutes.

He described the claim - included in the Government's September dossier - as "highly unlikely".

He said: "I think that was a fundamental mistake. I don't know exactly how they calculated this figure of 45 minutes in the dossier of September last year.

"That seems pretty far off the mark to me."

Asked if Mr Blair had relied on flawed intelligence or misinterpreted it, he replied: "They over-interpreted the intelligence they had."

Downing Street declined to be drawn on Dr Blix's remarks, only reiterating its established line that No 10 stood by the dossier.

Liberal Democrat foreign affairs spokesman Menzies Campbell said: "Day by day the case for an independent scrutiny of the lead up to the war against Iraq becomes irresistible.

"Only full disclosure can restore the reputation of this Government."

Transport Secretary Alistair Darling backed the Prime Minister against Ms Short's call for him to quit Downing Street, saying she risked "downgrading" her achievements by her continuing attacks.

Ms Short had earlier criticised Mr Blair over Iraq, foundation hospitals and student top-up fees.

Mr Darling said his former Cabinet colleague was not speaking for a significant proportion of Labour MPs.

Ms Short, who quit as International Development Secretary over the Iraq war and accused Mr Blair of leading Britain into the conflict on the basis of half truths and deceptions, warned the Prime Minister that he was losing touch with Labour's grassroots.

But there was support for Mr Blair, too, from former Northern Ireland Secretary Peter Mandelson.

Asked whether he was concerned that Labour might destroy Mr Blair in the same way the Tories brought down Margaret Thatcher, the Hartlepool MP said "the tiny handful of people who are shouting the odds" did not represent opinion in the Labour Party or the country.

At Saturday's Durham Miners' Gala, speaker after speaker railed against the leadership of the Labour Party, calling on Mr Blair to step down.

National Union of Mineworkers president Ian Lavery, who criticised the Government's white paper on energy, said: "Maybe it is time for Tony Blair to depart. The New Labour project has been an abject failure."

Aslef general secretary Mick Rix said: "Let's get rid of Tony Blair and take over the party.

"We have seen many trade unionists elected to positions of influence and prominence.

"Hopefully, not before long, we'll be in power where we rightfully should be."

NUM general secretary Dave Hopper said: "There is a great optimism that we can change the direction that the Labour Party has taken in the last six to seven years."