The British Government wrote to the intelligence and security services to admit there were failings in its controversial second dossier on Iraq's weapons, it has emerged.
Campbell expressed concern about dossier
A Downing Street spokesman said Alastair Campbell, Prime Minister Tony Blair's director of communications, told the agencies "far greater care" would be taken in dealing with anything which might impact on their reputation and work.
February's dossier - the second on Iraq - was widely criticised when it emerged part of it was copied from a 12-year-old thesis by an American student.
The first document to make the case for war, published last September, is being investigated by MPs.
Downing Street has denied Mr Campbell's intervention amounts to an apology.
Two Iraq dossiers
Sept 2002: claimed Iraq had a continuing programme of chemical and biological weapons and had tried to acquire nuclear material from Africa
Feb 2003: drawn from a number of sources, but labelled "dodgy dossier" because parts plagiarised from 12-year-old thesis
The prime minister is under increasing pressure over the way the government made the case for war in Iraq, with coalition forces yet to find weapons of mass destruction.
The Conservatives have repeatedly called for an independent inquiry into whether intelligence documents were changed on the orders of Downing Street to strengthen the case for military action.
Meanwhile, intelligence officers are holding a "smoking gun" showing they came under pressure for evidence to use against Iraq in the run-up to the conflict, it is reported.
The Independent on Sunday says intelligence services were so concerned about demands made by Downing Street they kept detailed records of communications with the prime minister's staff.
The Sunday Telegraph reported Mr Campbell wrote a personal letter to Sir Richard Dearlove, chief of the Secret Intelligence Service (MI6).
The paper claims senior intelligence officers were furious the document had been made up of their own information combined with other sources.
In response to the paper's story, a Downing Street spokesman said: "Like many other stories on weapons
of mass destruction, this one is totally overblown.
"What happened in the wake of the controversy surrounding the second dossier was that Alastair Campbell spoke to those who had been responsible for its production to demand tighter procedures.
"He also assured the (intelligence) agencies that far greater care would be taken in dealing with anything that might impact on their reputation or their
The spokesman added: "Alastair is on excellent terms with the head of the Secret Intelligence Service."
Security bosses were told to tighten up procedures
Downing Street said it would not characterise it as a "letter of apology".
But a Conservative Party spokesman said: "We don't need an apology from Alastair Campbell - what we need is an independent inquiry into what was going on in Number 10 over the presentation of intelligence reports."
And Tory leader Iain Duncan Smith told BBC One's Breakfast with Frost programme: "The government's credibility, the prime minister's credibility is on the line because nobody believes what he says anymore.
"The only way to clear that up, and to make sure that our troops and our intelligence services are trusted in the next few years during the reconstruction, is to have an independent inquiry."
Chancellor Gordon Brown insisted that "the evidence and history will prove that Tony Blair made a courageous and the right decision over Iraq".
"I believe that all countries, when we passed the UN resolution... believed that there were and are weapons of mass destruction," he told the programme.
Home Secretary David Blunkett said: "I think it would have been better if we hadn't published that dossier because it was about the background to Iraq - it wasn't about the identification of WMD."
The letter had been "an honest appraisal" by Mr Campbell, but a line should be drawn under the issue, he told BBC's The Politics Show.
The second dossier, entitled Iraq: Its Infrastructure of Concealment, Deception and Intimidation, was distributed to journalists on Mr Blair's trip to Washington to discuss plans for war.
There was a furore when it was revealed parts were lifted from a thesis on the internet.
The Sunday Telegraph claims it was not first cleared by the Joint Intelligence Committee before being published.
That committee approved the first dossier, published in September, which is now subject to an inquiry by the Commons foreign affairs select committee.
The Intelligence and Security Committee is also investigating that report, which the government denies was doctored in order to muster support for war.
A key point of contention in the first dossier was the claim that Iraq could launch a chemical attack in 45 minutes.
Downing Street is standing by the intelligence provided in that report.