But the committee criticized the government's presentation of the claim that Iraq was prepared to launch some chemical and biological weapons on 45 minutes notice.
That claim was prominent in the dossier published by the government in September as it laid out its case for military action in Iraq.
The committee, drawn from both houses of Parliament, was also critical of Defense Secretary Geoff Hoon and said his Ministry of Defense had been "unhelpful and potentially misleading" by initially failing to disclose that some of its staff had expressed concerns about the dossier.
"We are disturbed that after the first evidence session (before the committee), which did not cover all the concerns released by the intelligence staff, the defense secretary decided against giving instructions for a letter to be written to us outlining the concerns," the report added.
Iain Duncan Smith, leader of the opposition Conservative Party, repeated his call for Hoon to resign. "The committee has accused him of misleading and withholding information," Duncan Smith said.
However, Foreign Secretary Jack Straw said the prime minister and the Cabinet backed Hoon. "I am in no doubt that the Defense Secretary should and will continue in his post," Straw said.
Blair's government has been under increasing pressure because coalition forces have not found evidence of Iraqi weapons of mass destruction — which was the heart of the government's case for military action.
The government has been embroiled in a dispute with the British Broadcasting Corp. over a report that cited an unidentified source as saying the government overruled intelligence advice to "sex up" the dossier by including the 45-minute claim, and that it probably knew the claim was wrong.
The BBC reporter, Andrew Gilligan, subsequently said his source had blamed Blair's communications chief, Alastair Campbell, for insisting on including the claim.
The Intelligence and Security Committee rejected those charges, and accepted the government's assertion that the Joint Intelligence Committee which prepared the dossier did not come under political pressure.
The chairman of the Joint Intelligence Committee, John Scarlett, assured the ISC that he did not "at any time feel under pressure, nor was he asked to include material that he did not believe ought to be included in the dossier," Thursday's report said.
"We accept this assurance. We are content that the JIC has not been subjected to political pressures and that its independence and impartiality has not been compromised in any way. The dossier was not 'sexed up' by Alastair Campbell or anyone else."
However, the committee criticized the way the 45-minute claim was presented.
"As the 45 minutes claim was new to its readers, context of the intelligence and any assessment needed to be explained. The fact that it was assessed to refer to battlefield chemical and biological munitions and their movement on the battlefield, not to any other form of chemical or biological attack, should have been highlighted in the dossier."
The committee also examined the dossier's disputed claim that Iraq had been seeking to buy "significant quantities" of uranium in Africa, presumably for a nuclear weapons program.
The International Atomic Energy Agency said that documents which claimed Iraq had sought uranium in Niger were forgeries.
The committee said British intelligence officials insisted that they had two independent sources for the claim. "We have questioned the (Secret Intelligence Service) about the basis of its judgment and conclude it is reasonable," the report said.
The White House this summer withdrew the claim, saying it was based on bad intelligence.
The House of Commons Foreign Affairs Committee, in a report issued July 7, also absolved the government and Campbell. Campbell has since resigned.
The apparent suicide of government weapons adviser David Kelly, who was identified as the source of the BBC report, is the subject of a continuing judicial inquiry led by an appeals judge, Lord Hutton.
That inquiry has uncovered more troubling evidence for Blair.
Hutton's inquiry has heard evidence that intelligence officials within the Ministry of Defense were unhappy with the dossier and a senior official wrote to his superiors to express such concern.
Brian Jones, who until recently headed a section of the Defense Intelligence Staff, told the Hutton inquiry that some of his staff felt that the dossier was "over-egging certain assessments."
And an aide to Blair, Jonathan Powell, was found to have written in an email that the evidence uncovered did not point to an "imminent threat" from Iraq.