Cook, who resigned from government in protest ahead of the war, also
claims Blair "deliberately crafted suggestive phrasing" to mislead the public into thinking there was a link between Iraq
and al Qaeda.
The claims are included in a book based on diaries Cook kept during
the tense period in the run-up to war, extracts of which were published in The Sunday Times.
Blair's Downing Street office dismissed the claims as "absurd."
"The idea that the prime minister ever said that Saddam Hussein didn't
have weapons of mass destruction is absurd," a spokesman said.
"His views have been consistent throughout, both publicly and privately,
as his Cabinet colleagues know.
"Robin Cook's views are well known and have been expressed many times
In his book, "Point of Departure," the former foreign secretary said
he was most troubled by a conversation he had with Blair on March 5, two weeks before the war began.
At the time, Britain was still trying to get a new U.N. resolution
to authorize war, and Cook was still in government as leader of the House of Commons.
Cook said he told Blair that briefings he had received made it clear
that Saddam had no weapons of mass destruction "in a sense of weapons that could strike at strategic cities."
He said he asked the prime minister if he was concerned that Saddam
might use chemical munitions against British troops.
Cook said Blair's response was: "Yes, but all the effort he has had
to put into concealment makes it difficult for him to assemble them quickly for use."
Cook said the prime minister's response left him "deeply troubled."
"Tony did not try to argue me out of the view that Saddam did not
have real weapons of mass destruction that were designed for strategic use against city populations and capable of being delivered
with reliability over long distances," Cook wrote.
Cook said he had also expressed that view to John Scarlett, chairman
of the Joint Intelligence Committee, and that Scarlett had similarly failed to correct him.
"I had now expressed that view to both the chairman of the JIC and
the prime minister and both had assented to it," Cook wrote.
Cook said he had no reason to doubt that Blair believed that Saddam
had WMD ready for firing within 45 minutes in September 2002, when the claim was first aired in a government dossier on Iraqi
Cook quit the government in protest on the eve of war.
But he added: "What was clear from this conversation was that he did
not believe it himself in March."
Cook said he was also troubled by his March 5 exchange with Blair
because "the timetable to war was plainly not driven by the progress of the U.N. weapons inspections.
"Tony made no attempt to pretend that what (then-chief U.N. weapons
inspector) Hans Blix might report would make any difference to the countdown to invasion," Cook wrote in a March 5 entry.
In the first memoir from a member of Blair's cabinet, Cook also writes
that Blair was "far too clever" to allege there was a real link between Saddam and al Qaeda.
"But he deliberately crafted a suggestive phrasing which in the minds
of many views must have created an impression, and was designed to create the impression, that British troops were going to
Iraq to fight a threat from al Qaeda," Cook wrote in a February 6 entry.
Cook also said there was near mutiny in the Cabinet when it first
discussed military action in Iraq -- which suggests there was greater opposition to war than the government has acknowledged.
Cook said two Cabinet ministers -- Home Secretary David Blunkett and
Trade and Industry Secretary Patricia Hewitt -- raised objections to Blair's policy on Iraq as early as March 2002, leaving
the prime minister "out on a limb".
It was "the nearest thing I've heard to a mutiny in Cabinet," Cook