The BBC will present fresh details about how the Iraqi weapons dossier was allegedly "sexed up'' by Downing Street and accuse Alastair Campbell of giving "inaccurate'' evidence to the official inquiry into the affair.
Publication of the claims, in the next 48 hours, will reignite the unprecedented row just as the Blair Government appears keen to damp it down. According to senior sources, the corporation has decided at the highest level not to give in to the relentless pressure from the Government.
Journalists and officials at the BBC have spent the weekend poring over the testimony given by Mr Campbell to the Foreign Affairs Select Committee.
According to the sources they have discovered "inaccuracies and inconsistencies'' in what the Prime Minister's communications chief told MPs. Andrew Gilligan, the BBC reporter who has been the focus of government attacks, will produce further information on how the intelligence services were supposedly pressured by Mr Campbell about the "45-minute threats'' posed by Saddam Hussein, which appeared in the first Downing Street dossier last September.
An investigation is under way, allegedly at the behest of Number 10, to hunt down Mr Gilligan's source.
Mr Gilligan, the defence and diplomatic correspondent of Radio 4's Today programme, has told Richard Sambrook, the head of news at the BBC, the identity of his informant. Greg Dyke, the director general, has been given details of the source but not his name.
Sources within the intelligence services have indicated that they will be "combative'' if the Government attempts to start a witch-hunt to find out those responsible for leaks to a number of journalists about the unhappiness within the services over how intelligence on Iraq was manipulated.
The hierarchy at the BBC is also ready for a prolonged confrontation with Downing Street over the affair. Both Mr Dyke and Gavyn Davies, the chairman of the board of governors, have links with New Labour. Taking on the Government at this stage is seen as a measure of their independence, according to BBC sources.
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