Britain's pre-war intelligence on Iraq's armaments had "serious flaws" but Prime Minister Mr Tony Blair was not personally responsible, a top-level inquiry found today.
"No single individual was to blame. This was a collective operation," Lord Butler told reporters after releasing a report that also said Saddam Hussein had no significant banned weapons ready for use prior to the US-UK invasion.
His findings mirrored last week's Senate committee report that lambasted US intelligence services for exaggerating the threat from Iraq, but found no sign President George W. Bush had pressured analysts to reach pre-set conclusions.
Today's long-awaited report by former top British civil servant Lord Butler concluded that Iraq "did not have significant - if any - stocks of chemical or biological weapons in a state fit for deployment nor developed plans for using them".
The government's Joint Intelligence Committee (JIC) strove to put together a dossier on Iraq's weaponry in 2002 reflecting available intelligence but was under "strain" in a politically charged climate as they sought to be objective, it added.
Lord Butler said in future there should be clearer lines dividing those assessing intelligence and those advocating policy.
But there was "no deliberate attempt on the part of the government to mislead," he added.
In the now notorious September 2002 dossier compiled by the JIC, Mr Blair stated that Iraq could deploy some weapons of mass destruction within 45 minutes of an order to do so.
No such weapons have been found more than a year after Saddam was overthrown.
"We conclude that it was a serious weakness that the JIC's warnings on the limitations of intelligence underlying its judgments were not made sufficiently clear in the dossier," said the report, five months in the making.
"Our view, having reviewed all of the material, is that judgments in the dossier went to (although not beyond) the outer limits of the intelligence available.
"The prime minister's description, in his statement to the House of Commons on the day of the publication of the dossier, as 'extensive, detailed and authoritative' may have reinforced this impression."
The report said the 45 minutes claim should not have been included in the dossier without stating precisely what it referred to. The fact that it was, led to suspicions that it was there for "its eye-catching character".
But Lord Butler apportioned no blame for the quality of the intelligence or how it was used in the government's case for war. He said Mr John Scarlett, who headed the JIC and has now been promoted to run Britain's Secret Intelligence Service, should not be punished.
"We conclude that if intelligence is to be used more widely by governments in public debate in future, those doing so must be careful to explain its uses and limitations," the report said.
"It will be essential too that clearer and more effective dividing lines between assessment and advocacy are established when doing so."
Like his ally President Bush, Mr Blair has seen his popularity tumble over Iraq and now risks backlash at the polls.
Yet most analysts still see Mr Blair leading the Labour Party into an election expected in 2005 - and winning it.
Analysts said the Butler report would be a relief to Mr Blair despite its criticism of intelligence.
"I would think this is the best that the Prime Minister and the government could have hoped for. It looks to be as if he has been more or less left out of the circle of blame," Mr John Benyon, politics professor at the University of Leicester, said.