Tony Blair has failed to come to the aid of the beleaguered defence secretary amid claims that he misled MPs.

Quizzed on a leaked report which raised fresh doubts about Geoff Hoon's future, Blair called on MPs to "wait and see" what the final document says when it is released tomorrow.

Whilst he praised the "magnificent victory" achieved under Hoon in the Gulf, the prime minister failed to say whether the minister would remain in post.

The comments came after Iain Duncan Smith challenged Blair to say whether he would "dismiss" Hoon once the intelligence and security committee report is made public.

Following a leak to the Evening Standard newspaper Duncan Smith said "senior Downing Street officials" were already briefing against the embattled Cabinet minister.

A defiant prime minister insisted allegations that Number 10 had leaked the report were "completely untrue".

Quizzed on the issue in the Commons, Blair repeatedly denied that Number 10 was hanging the Cabinet minister out to dry.

"If he actually has evidence that somebody from Downing Street has put this report into the newspapers, perhaps he would produce it now because I believe that to be completely untrue," he told the Tory leader.

Calling on the prime minister to end the uncertainty about Hoon's future, Duncan Smith hit back.

"How can the prime minister justify leave him twisting in the wind when it is in his power to end all the uncertainty and speculation and publish this report right now," he said.

Duncan Smith added that the latest development was a further example of the endemic culture of spin and deceit.

"Isn't this leaked report another nail on the coffin of this government?" he asked.

"You can get rid of Campbell, you can even get rid of the defence secretary but the lying and the spinning won't stop until we get rid of this prime minister."

Blair said the opposition leader was jumping to conclusions for political reasons.

"It is a measure of his objectivity that he has decided what this report says before it is actually published," he told MPs.

"Why doesn't he wait and see what the report says when it is published tomorrow."