How that dossier got tougher and tougher

The dossier that made the case for war against Iraq was dramatically strengthened before its publication on 24 September, documents published by the Hutton inquiry reveal. It went through four drafts in 19 days, beginning with no reference to the claim that Saddam Hussein could launch a chemical or biological weapons strike in 45 minutes.

But in the draft of 10 and 11 September it says: "Iraq continues to have the capability to produce chemical and biological weapons and has probably already done so."

The word "probably" is not in the final version, in which Tony Blair states boldly: "The assessed intelligence has established beyond doubt ... that Saddam has continued to produce chemical and biological weapons."

An early draft of the Prime Minister's foreword says: "The case I make is not that Saddam could launch a nuclear attack on London or another part of the UK (he could not)."

The 10/11 draft of the dossier says reports that Iraq could produce smallpox were "uncorroborated". It also says Saddam abandoned work on a radiological bomb after failing to progress beyond the "research stage". All of these comments about the risk from Iraq were missing in the dossier's final version a fortnight later.

On the issue of whether Iraq still had deadly weapons from before the 1991 Gulf War, the 11 September draft says: "We judge that Iraq has retained production equipment and at least small amounts of chemical agent and precursors."

Jack Straw, the Foreign Secretary, was singing from a very different songsheet as war began. He stated for certain that Iraq had a stockpile of 10,000 litres of anthrax.