British Prime Minister Tony Blair:

Blair, who led the Labour Party to a crushing victory in 1997 after 18 years in opposition, is facing the biggest crisis of his career after the apparent suicide of former UN weapons inspector David Kelly.

The prime minister has staked his reputation on a decision to join the United States in waging war on Iraq despite hostile public opinion.

Blair, 50, has rejected calls to resign but pledged full cooperation with a judicial inquiry into Kelly's death, admitting: "In the end, the government is my responsibility."

Dr David Kelly:

Microbiologist Kelly, who apparently killed himself by cutting his wrist with a knife, was a defence ministry advisor thrust unexpectedly into the centre of a bitter row between Downing Street and the BBC.

On May 22, the 59-year-old father of three met BBC reporter Andrew Gilligan for a chat which, according to the broadcaster, formed the basis of a controversial report saying the government had exaggerated the threat from Iraqi weapons.

Andrew Gilligan, BBC defence correspondent:

Gilligan, and the vexed issue of whether he misrepresented the views of Kelly, lie at the very heart of the row between the government and the BBC.

Formerly defence correspondent for the Sunday Telegraph, Gilligan was recruited for BBC radio's flagship morning news programme "Today" three years ago with a particular brief to uncover fresh stories.

Alastair Campbell, Blair's director of communications:

Campbell, a former tabloid journalist dubbed the "sultan of spin", joined Blair's side in 1994 as his official spokesman, but took a more low-profile role in 2001 amid concern he was overshadowing even the man he was supposed to vaunt.

But Campbell, 46, hit the headlines after Gilligan alleged he was responsible for the insertion of a sensational one-sentence claim into a government dossier published in September that Iraq could deploy chemical or biological weapons in just 45 minutes.

A parliamentary probe cleared Campbell of exerting "improper influence" in the drafting of the file, but critics continue to argue the episode show he should quit Downing Street.

Secretary of Defence Geoff Hoon:

Geoff Hoon, 49, the unflappable Secretary of Defence, was one of Blair's closest lieutenants during the war on Iraq, giving regular press briefings on the conflict.

Now the Cambridge-educated lawyer faces questions about his role in the exposure of Kelly as the anonymous source behind the BBC story after the media reported that his press office helped journalists to identify the scientist.

Richard Sambrook, BBC director of news:

Sambrook has been at the front line of the corporation's vigorous defence of its actions throughout the row, and could face a bleak future if the story in question is found to be compromised.

The 47-year-old has worked his way through the BBC's ranks since joining as a lowly radio sub-editor in 1980, eventually taking overall control for the corporation's 2,000 journalists in February 2001.

Greg Dyke, BBC Director-General

Dyke is an unlikely candidate to be at the centre of such a bitter row with the government, given that his appointment as BBC director-general at the start of 2000 was almost scuppered by his perceived closeness to Blair.

Critics said the 57-year-old former commercial television executive was not impartial after it emerged he had led a fundraising drive for Blair. But Dyke now faces calls to resign over the BBC's handling of the story.

Gavyn Davies, chairman of BBC Board of Governors

Davies is also not a natural adversary for Blair's Labour government, and has close links to the administration, especially Chancellor of the Exchequer Gordon Brown, for whom his wife works as personal secretary.

Aged 52, Davies took the helm of the BBC's Board of Governors in October 2001 after a long -- and extremely lucrative -- finance career which saw him become chief international economist for US investment bank Goldman Sachs.

Lord James Hutton:

One of Britain's most senior judges, 72-year-old Hutton is heading a judicial inquiry into the events leading up to Kelly's death.

One of 12 judges in the country's highest court, the House of Lords, among his most high-profile cases was that of controversial Chilean General Augusto Pinochet.

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