Dr David Kelly supported military action against Iraq even though he believed the threat posed by its weapons of mass destruction was "modest", he wrote in a report that came to light yesterday.
As Dr Kelly's widow and one of his daughters prepared to give evidence to the Hutton inquiry via a video link today, an article written by the government scientist became known. It said military action was the only way of "conclusively disarming" Saddam Hussein.
The article, written anonymously for a report on Iraq shortly before the war but never published, has been sent to Lord Hutton's inquiry into Dr Kelly's death. His views, those of an expert on Iraq's WMD, could give Tony Blair some unexpected relief amid growing doubts the war was justified.
Dr Kelly wrote: "Iraq has spent the past 30 years building up an arsenal of weapons of mass destruction. Although the current threat presented by Iraq militarily is modest, both in terms of conventional and unconventional weapons, it has never given up its intent to develop and stockpile such weapons for both military and terrorist use."
The scientist dismissed the apparent co-operation by Iraq with UN inspectors before the war, saying that Saddam's regime "continues to mislead the international community. It is difficult to imagine co- operation being properly established unless credible Iraqi officials are put into place by a changed Saddam."
Dr Kelly argued: "After 12 unsuccessful years of UN supervision of disarmament, military force regrettably appears to be the only way of finally and conclusively disarming Iraq.
"War may now be inevitable. The proportionality and intensity of the conflict will depend on whether regime change or disarmament is the true objective. The US, and whoever willingly assists it, should ensure that the force, strength and strategy used is appropriate to the modest threat that Iraq now poses.
"The long-term threat, however, remains Iraq's development to military maturity of WMD - something that only regime change will avert."
Jack Straw, the Foreign Secretary, insisted the decision by the House of Commons to approve military action was still justified. He told the BBC's Breakfast with Frost programme: "I believed that military action had been necessary in the light of Saddam's past record of defiance of the United Nations and the unanswered questions about his weapons programmes."
He refused to predict that the Iraq Survey Group now hunting for WMD would find any. "I can't say precisely what will be discovered. No one can say that," he said.
'ONLY REGIME CHANGE WILL AVERT THREAT'
This is an edited extract from Dr Kelly's article on Iraqi weapons:
"Some of the chemical and biological weapons deployed in 1991 are still available, albeit on a reduced scale. Aerial bombs and rockets are readily available to be filled with sarin, VX and mustard or botulinum toxin, anthrax spores and smallpox. More sophisticated weaponry, such as spray devices associated with drones or missiles with separating warheads, may be limited in numbers, but would be far more devastating if used.
"The threat from Iraq's chemical and biological weapons is, however, unlikely to substantially affect the operational capabilities of US and British troops. Nor is it likely to create massive casualties in adjacent countries. Perhaps the real threat from Iraq today comes from covert use of such weapons against troops or by terrorists against civilian targets worldwide. The link with al-Qa'ida is disputed, but is, in any case, not the principal terrorist link of concern. Iraq has long trained and supported terrorist activities and is quite capable of initiating such activity using its security services.
"The long-term threat, however, remains Iraq's development to military maturity of weapons of mass destruction - something that only regime change will avert."Reuse content