Tony Blair's press chief Alastair Campbell has vehemently denied "sexing up" evidence in an important dossier about Iraq's alleged weapons of mass destruction.
Plagiarising part of a thesis was 'a mistake'
But he told MPs he regretted the mistakes made over the so called "dodgy dossier" published later - in February this year.
The Downing Street communications director was grilled by MPs on the Commons foreign affairs committee investigating whether the UK Government exaggerated the case for invading Iraq.
This was the performance the whole of Westminster had been waiting for with bated breath since this row erupted
He demanded that the BBC apologise for what he called the "lie" that he had exaggerated evidence in the government's flagship dossier about Iraq's weapons, which was published last September.
Committee chairman Donald Anderson opened Wednesday's hearing by saying Mr Campbell was accused of embellishing the evidence in a way that misled the House of Commons and the public in his "zeal" to make the case for war.
Weapons launch claim
BBC defence correspondent Andrew Gilligan reported last month that a senior British official had told him that the government's first dossier on Iraq's weapons programme had been "sexed up" at Downing Street's request.
In particular, it was alleged a claim that Downing Street asked for extra prominence to be given to a claim that Iraq could launch a chemical or biological strike within 45 minutes of an order.
Mr Campbell insisted intelligence agencies made the 45 minute claim and suggestions he had hyped it up were a "lie".
"It is completely and totally untrue that I in any
way over-rode that judgement, sought to exaggerate that intelligence, sought to
use it in any way that the intelligence agencies weren't 100% content with," he went on.
Indeed, the Joint Intelligence Committee had written Tony Blair's foreword to the dossier, he said.
Are we really so cynical that we think any prime minister, is going to make prior decisions to send British forces into conflict and wouldn't rather avoid doing that
He continued: "I think it is time the BBC apologised to us in relation to the 45 minutes point."
Mr Campbell said he was prepared for the MPs to see all the drafts of the September dossier if the chairman of the joint intelligence committee approved that move.
In a statement, the BBC said: "We do not feel the BBC has anything to apologise for. We regret that Alastair Campbell has chosen to accuse Andrew Gilligan and the BBC of lying."
Mr Campbell also commissioned February's "dodgy dossier", which copied material from an academic thesis about Iraq.
He said plagiarising part of an academic thesis was "a mistake", but set that within the context of many documents being sent to a "round-the-clock, round-the-world" media.
US-led searching has so far drawn a blank
Foreign Secretary Jack Straw on Tuesday called the document an "embarrassment" for the government.
Mr Campbell said the government apologised to the Californian student Ibrahim al-Marashi, whose thesis was used.
Staff in the government's Communications Information Centre (CIC) had drafted the February dossier as a briefing paper for journalists, he said.
It was designed to show new intelligence about how Iraq was hiding weapons of mass destruction.
The "mistake" during the drafting process was that they had taken parts of the academic thesis from a Middle Eastern journal and failed to attribute it.
This error was not realised by others working on the document, who had altered parts of Dr al-Marashi's work thinking they were making the government's own work more accurate, said Mr Campbell.
He had only discovered what had happened when it was uncovered by the BBC and Channel 4, he explained.
Conservative MP Sir John Stanley said the way Mr Blair had presented the document to the Commons made MPs wrongly think it had the "seal of approval" from intelligence chiefs.
He suggested the inadequate way Mr Campbell had briefed the prime minister had caused him to mislead Parliament.
The spin doctor replied: "That is a very, very grave charge and I think it is one I reject."
He denied reports that he had sent a "grovelling" apology note to intelligence chiefs about the "dodgy dossier" but he had spoken to them "to explain that something had gone wrong".
No 'glib' war
Mr Campbell denied former cabinet minister Clare Short's claim that Mr Blair had agreed with US President George Bush last September to attack Iraq in February.
Instead, the prime minister had worked "flat out" for agreement at the United Nations as a way of avoiding conflict, said Mr Campbell.
It was wrong to think the government had "glibly" decided to go to war and then tried to "sex up" the dossier to win public backing.
"I know scepticism is fine ... but are we really so cynical that we think the prime minister, any prime minister, is going to make prior decisions to send British forces into conflict and wouldn't rather avoid doing that?"
Mr Campbell initially refused to appear before the House of Commons committee's inquiry.
But Downing Street said he had changed his mind after unspecified newspaper allegations made at the weekend.