Jack Straw has told MPs the claim Saddam Hussein could use weapons of mass destruction within 45 minutes has been officially withdrawn.
The ISG report said Iraq wanted to recreate Iraq's WMD capability
The claim was at the heart of an unprecedented row between the BBC and the government which led to the death of David Kelly and the Hutton inquiry.
But Mr Straw insisted that "even with hindsight" knowing that Saddam had not had WMD, the war had been right.
He said there was evidence Iraq was trying to restart weapons programmes.
Mr Straw, UK foreign secretary, said: "The Butler committee concluded that the validity of the line of reporting which included the 45-minute intelligence had come into question."
He added "the chief of the Secret Intelligence Service has written to the Intelligence and Security Committee formally withdrawing" it.
But he told MPs in the Commons: "I do not accept, even with hindsight, that we were wrong to
act as we did."
A report by the Iraq Survey Group concluded last week that Iraq was free of weapons of mass destruction by the mid-1990s.
For the Conservatives, Gary Streeter said Tony Blair was guilty of "stripping out" caveats from intelligence ahead of presenting it to the public.
"[Mr Blair] did not behave as a British prime minister should," he said adding that the situation in Iraq would be "far less grave" had there been proper planning for post-war reconstruction.
Mr Streeter urged "a full apology - not an apology for the intelligence but
an apology for the way that the intelligence was conveyed by the government to the country".
The foreign secretary insisted intelligence shared with MPs was an accurate reflection of the views held by the Joint Intelligence Committee at that time.
"It is very, very important that the House understands that the evidence we put forward was a view widely shared at the time by other foreign intelligence agencies as well, as it happens, by [UN chief weapons inspector] Hans Blix."
That was a reference to documents released by the Foreign Office which show British officials presented Mr Blix with an early draft of the government's intelligence dossier in September 2002 - two weeks before publication.
One official, Adam Bye, noted that Dr Blix had liked the section on chemical, biological and nuclear weapons which he did not believe exaggerated the facts.
Lib Dem foreign affairs spokesman Sir Menzies Campbell meanwhile argued that 12 months before the invasion of Iraq the "true objective" was already regime change.
Former Labour foreign secretary Robin Cook argued that given the Iraq Survey Group had found Saddam Hussein posed no "immediate threat" with his weapons it would have been wise to give UN inspectors more time before embarking on the war.
Earlier Mr Straw paid tribute to murdered UK hostage Ken Bigley who was beheaded by Islamic extremists last week.
The British foreign secretary sent his "condolences and deepest sympathy" to Mr Bigley's family.
"I rack my brains about whether there were other things we could have done," he said before adding: "I don't think there were."
The official withdrawal of some of the intelligence is the first time the House of Commons has been told the claim that Saddam could use WMD within 45 minutes of an order being given was now officially discredited.
The claim was a key element in the government's dossier on Iraq's weapons published in September 2002.
It became the focus of controversy after the BBC Today programme's Andrew Gilligan reported claims, in May 2003, that the government "probably knew" it was wrong before putting it in the dossier.
Those claims were vehemently denied by Downing Street and led to the naming Mr Gilligan's source, Dr David Kelly, who later committed suicide. His death was investigated by the Hutton Inquiry.
A wider probe into intelligence on Iraq's WMDs, the Butler inquiry, in July said MI6 had said the claim "has come into question".
He said it should have had caveats attached to it in the dossier but stressed there was no deliberate distortion and said there was no evidence the inquiry had seen to suggest the government had not acted in good faith.