Crucial changes to the dossier that set tone for conflict

The full extent of the changes made to the Government's September 2002 dossier on Iraq's weapons of mass destruction became clear for the first time yesterday, when the Hutton inquiry into David Kelly's death published all the drafts on its website.

The document published on 24 September went through four drafts in less than three weeks, after a meeting chaired by the Downing Street director of communications, Alastair Campbell, decided on 5 September that a version prepared over preceding months needed a "substantial rewrite".

The most dramatic changes occurred between 10 and 16 September. The second of these is close to the final published version in its structure and overall tone, though in the eight days before publication there is a crucial change concerning Iraq's readiness to use chemical and biological weapons. The 16 September version states that the Iraqi military "may be able to deploy chemical or biological weapons" within 45 minutes of an order to do so, whilst the published version states that they "are able to deploy" these weapons within that timeframe.

The two versions produced before 11 September last year are quite different. The 10/11 September draft begins with a long historical review of Saddam Hussein's rule, some of which is relegated to the end of the published version but is mostly omitted. That draft contains significantly more cautious language.

On the critical issue of Iraq's continued production of chemical and biological weapons, it states: "Iraq continues to have the capability to produce chemical and biological weapons, and has probably already done so." But the crucial word, "probably", finds no expression in the published dossier, which portrays the ongoing production as a certainty. In the published version, the Prime Minister's foreword states confidently that "the assessed intelligence has established beyond doubt ... that Saddam has continued to produce chemical and biological weapons".

On the second major issue, about weapons that Iraq may have retained from before 1991, the earlier dossier states: "We judge that Iraq has retained production equipment and at least small amounts of chemical agent and precursors." The reference to "small amounts" was at odds with the implication of later claims in the published dossier, and the comments of government ministers in the run up to the conflict. The Foreign Secretary, Jack Straw, said on the eve of the invasion "we know" Iraq had 10,000 litres of anthrax.

A number of passages in earlier versions, which discount or play down Iraq having certain stocks of weapons, are omitted from the published version. The 10/11 September draft dismisses reports about smallpox production as "uncorroborated". It adds that Iraq "never progressed beyond the research stage" and later abandoned work on a radiological bomb.

An earlier draft of Tony Blair's foreword also seeks to reassure: "The case I make is not that Saddam could launch a nuclear attack on London or another part of the UK (he could not)." None of these assessments were kept for the published version.

There is no firm indication from the material released by Lord Hutton of who ensured these changes were made. The transition between the drafts of 5 September and 10/11 September was under the guidance of John Scarlett, chair of the Joint Intelligence Committee (JIC), and his deputy, Julian Miller, both senior officials in the intelligence community. In the days after 11 September, it is unclear from the material available who was shepherding the re-drafting, but Mr Scarlett objected to the it being referred to in Mr Blair's foreword as "the work of the JIC".

In fact, in the draft drawn up by him, dated 10/11 September, there are several simple factual mistakes that are corrected in the later version. That earlier version has the date on which UN inspectors were withdrawn on President Bill Clinton's orders in December 1998 wrong by three days; it misspells Halabja; it has the name of the main Kurdish party wrong (calling it the Kurdish, not the Kurdistan, Democratic Party); and it claims the resolution establishing the UN inspectors in 1991 was passed unanimously (whereas Cuba voted against, and two other states abstained).

If it was Mr Campbell in charge, he can take credit for correcting at least some of the spooks' more straightforward errors.