Mr Campbell has gone on the attack against the BBC

In a letter to the corporation, Number 10 press chief Alastair Campbell has said there is little point in the two sides having more exchanges until next week's judgement on the affair from an MPs' committee.

But on Monday, Tony Blair's spokesman said the government was not "backing down one inch" and accused the BBC of a "deafening silence" over the central point in the dispute.

The BBC has refused to apologise for its report that a senior intelligence official had said last September's Iraq dossier was "sexed up" at Downing Street's request.

Mr Blair's spokesman said: "The BBC stating 'we stand by our story' does not answer the question 'was the allegation true or false?'"

He accused the corporation of trying to move the goalposts by debating the whereabouts of weapons of mass destruction.

The House of Commons foreign affairs select committee is investigating the government's use of intelligence material in the build-up to the Iraq war, and will report on Monday 7 July.

Standing by story

On Sunday, in a new letter to the BBC, Mr Campbell accused the broadcaster of being unwilling to admit it was "standing by a story that is simply untrue".

He claimed the BBC had broadcast a "manifestly inadequate piece of journalism".

It's deeply disappointing that the BBC are not prepared to accept that these allegations are not true Geoff Hoon, Defence Secretary Q&A on the dossier row

In response the BBC's head of news, Richard Sambrook, said: "The real question for the BBC is were we right to report what we actually said, when we said it? We believe the answer is 'Yes'."

He said the BBC has not accused the government of lying.

He further defended the BBC, saying it had more evidence to present to the committee next week.

Health Secretary John Reid had re-entered the increasingly bitter row, appearing in the BBC One's Breakfast with Frost on Sunday.

And Defence Secretary Geoff Hoon said he thought the BBC should retract the claim.

"It's deeply disappointing that the BBC are not prepared to accept that these allegations are not true," he told BBC Radio 4's Westminster Hour on Sunday.

Meanwhile, one of the BBC's fiercest critics has come to the defence of the corporation.

Writing in The Independent, former Tory Party chairman Norman Tebbit says Mr Campbell and Tony Blair's anger over the BBC story "springs from the failure of their policy on Iraq".

Acrimonious exchanges

Of the BBC in general, which he argues has been staffed by Mr Blair with "cronies and patsies", Lord Tebbit says "it does not invent an elaborate lie against government, least of all one it did so much to help elect".

The row began when the BBC reported last month that security services were unhappy that intelligence material was used by Tony Blair in a way that effectively exaggerated the threat from Iraq.

The BBC report highlighted as a "classic example" the uncorroborated claim, included in Mr Blair's foreword to the September dossier, that Saddam could launch weapons of mass destruction within 45 minutes of the order being launched.

An intelligence source was reported as saying this claim "wasn't in the original draft. It was included in the dossier against our wishes because it wasn't reliable".