Kelly inquiry: The case against the BBC

First, Downing Street maintains, the BBC broadcast a false report and then refused repeated opportunities to apologise for doing so.

Alastair Campbell, Tony Blair's chief spin doctor and a former tabloid reporter, said this was an extreme example of falling standards of accuracy at the BBC.

The Government says it was Andrew Gilligan and not Mr Campbell who was guilty of "sexing up". It maintains the BBC reporter was never told by David Kelly that Mr Campbell had pressed for the insertion of the "45 minutes" claim in to the September dossier.

Alternatively, if Dr Kelly did say so, he was speaking without adequate knowledge, and Mr Gilligan should have realised this. This second charge was raised after it became known that another BBC journalist, Susan Watts of Newsnight, had a tape recording in which Dr Kelly named Mr Campbell. However, neither Ms Watts, nor Gavin Hewitt, a third BBC journalist, had repeated Mr Gilligan's accusation of a government insertion to the dossier.

The Foreign Affairs Select Committee absolved Mr Campbell from the charge of interfering with the dossier, although this was done on a vote split on party lines.

The same committee, after recalling Mr Gilligan, strongly criticised him for allegedly changing his story and described him as an unsatisfactory witness. During his later appearance, Mr Gilligan maintained he never claimed Mr Campbell had attempted to alter the dossier, but he was merely reporting what he was told, a stance attacked by Tory and Labour members.

There is also criticism of the BBC over its description of Dr Kelly, the main source of Mr Gilligan's report. Although the reporter said he was a "government official who played a part in compiling the report", Richard Sambrook, the head of news, claimed the information came from a "senior intelligence source". Mr Sambrook's defence is that Mr Gilligan did not reveal to him the identity of the "mole".

The BBC had been put under intense pressure by the Government and its allies in the affair from the Murdoch press to reveal the source.

The BBC stood by the journalistic code of not naming sources. Mr Gilligan did, however, drop public hints which led to Dr Kelly to abandon his anonymity.

The BBC's byzantine politics, infighting and the personal animus some felt towards Mr Gilligan resulted in leaks to hostile newspapers.

Expected witnesses for the BBC: Andrew Gilligan; Susan Watts; Gavin Hewitt; Kevin Marsh, editor of Today ; Richard Sambrook; Greg Dyke, director general; Gavyn Davies, chairman of the board of governors.