One of the British government’s most respected advisers on Iraq’s WMD, an experienced weapons scientist who had worked with the United Nations to disarm Iraq during the 1990s, was the microbiologist David Kelly. As part of his job with the ministry of defence, he had regularly briefed journalists on an unattributable basis. On 22 May, he met and talked to a BBC radio journalist called Andrew Gilligan in a London hotel.

On 29 May, Andrew Gilligan alleged on the BBC’s flagship morning radio programme that the British government knew that a key piece of intelligence information presented to the public in the September 2002 dossier – that Saddam possessed WMD that could be launched within 45 minutes – was false. Gilligan sourced this allegation to “one of the senior officials in charge of drawing up that dossier”.

On 1 June, a newspaper hostile to the government published an article by Gilligan accusing Alastair Campbell, the prime minister’s chief of communications, of “sexing up” (embellishing) the dossier.

Campbell expressed outrage at the accusation of deceit, and was publicly scathing in criticism of the BBC’s coverage of the issue. Over the next month, both government officials and media engaged in strenuous efforts to identify the source of Gilligan’s allegations.

David Kelly confided to his superiors that he had spoken to Gilligan, but disputed the latter’s version of their conversation. Kelly’s name gradually became known to senior government, civil service, and intelligence officials, and to BBC executives.

After his name entered the public domain, Kelly was interviewed on 15 July by the foreign affairs committee of the lower house of parliament. In a strained, televised encounter, he denied being the source of Andrew Gilligan’s claim about Alastair Campbell’s role in the September 2002 dossier.

On 17 July, David Kelly left his home in the village of Southmoor, Oxfordshire to go for a walk. The next day his body was found, the cause of death loss of blood from a wound on his left wrist.

The government announced an independent public inquiry into the circumstances surrounding David Kelly’s death. It was led by a senior judge, Lord (Brian) Hutton, and lasted from 1 August to 25 September 2003.

Hutton published his report on 28 January 2004. It substantially exonerated Tony Blair, Alastair Campbell, and senior civil service and intelligence officials from blame; it was severely critical of Andrew Gilligan, and of the BBC’s management and editorial procedures.

After the Hutton report, the BBC’s chairman (Gavyn Davies) and director-general (Greg Dyke) resigned, followed by Gilligan. Most newspapers, and a large section of British public opinion, remained censorious of Tony Blair’s government, and regarded the report as a “whitewash” of its role.

As the public argument continued, the British government announced a further inquiry into the pre-war use of intelligence about Saddam’s WMD. Its chair is Lord (Robin) Butler, formerly head of the civil service and adviser to several prime ministers.