The notorious claim that Iraq could launch weapons of mass destruction within 45 minutes was not contained in an early draft of the controversial dossier, but the draft version did warn that the country had acquired weaponry intended to "terrorise, intimidate and destabilise", it was revealed today.

The draft written by John Williams, who at the time was head of press at the Foreign Office, and released today under the Freedom of Information Act, also said that Iraq "was actively assembling an arsenal of terror weapons with which to intimidate its neighbours and the wider international community".

Williams wrote that Iraq was "developing as a priority longer-range missile systems capable of targeting Nato (Greece and Turkey?)" and "covertly attempting to acquire technology and material for use in nuclear weapons".

But later in the document it was noted that Iraq would "find it difficult to produce fissile material [for nuclear weapons] while sanctions remain in place".

Williams also qualified concerns about the regime's chemical weapons capability by adding he could not be sure "whether these [weapons] have been destroyed".

The former Daily Mirror journalist referred to a number of atrocities committed by Saddam Hussein, who he said "maintained power by torture, rape and execution".

He referred to the late dictator's 1990 invasion of Kuwait and the 1998 chemical weapons attack on the village of Halabja, which killed some 5,000 Kurds.

The 45-minute claim became a key plank of the government's case for going to war and Tony Blair was subsequently accused of "sexing up" the dossier with the help of spin doctors.

The content of today's draft was considered significant because the government has claimed that the dossier eventually published in September 2002 was the work of the joint intelligence committee and its chairman, John Scarlett, and that the so-called "Williams draft" had little influence on the final version.

The Liberal Democrat foreign affairs spokesman, Edward Davey, said that the "core analysis" was "the same in both documents".

"The government cannot continue to deny the major role that spin doctors played in creating this dossier," he said.

"A press official should never have been drafting a document that ended up being used as the justification for going to war.

Researcher Chris Ames had campaigned for three years for release of the document before a tribunal finally ruled in his favour last month.

Williams noted in his dossier that the Foreign Office could not publish everything it knew because it "would put people's lives at risk" but added: "The public deserves as much knowledge as possible".

Read the draft here