Mark Thompson is to be questioned today by a parliamentary committee in the wake of controversy over large pay-offs to BBC executives.
The former director general, who left the corporation last year to take over at the New York Times, has accused BBC Trust boss Lord Patten and trustee Anthony Fry of ''fundamentally misleading'' members of a parliamentary committee.
His attack on his former colleagues came in a written statement submitted to the Commons Public Accounts Committee ahead of this afternoon's hearing.
At their last appearance before the committee in July, Patten and Fry, told MPs members of the Trust were not always included in decision-making.
Fry said there was ''some disconnect'' between what Thompson had written in a letter to the Trust about deputy director general Mark Byford's pay-off, in which he apparently declared it was within contractual arrangements, when the National Audit Office (NAO) found it was not.
Byford departed the BBC with a total payout of £949,000.
Thompson's written evidence describes Patten and Fry's committee appearance as containing ''important inaccuracies'' and being ''fundamentally misleading''.
He said: ''The insinuation that they were kept in the dark by me or anyone else is false.''
Patten said he was ''looking forward'' to coming back before the committee and had ''no concerns'' about what Mr Thompson has said.
He told ITN: ''There is one aspect of this very long deposition by Mr Thompson which I've found very curious, which is the focus on Mark Byford and his pay-off because as anybody that works at the BBC knows that happened before I became Chairman of the Trust so it's slightly difficult to see how I could have been responsible for that.''
A Trust spokesman described Thompson's evidence as ''bizarre'' and said the organisation rejected ''the suggestion that Lord Patten and Anthony Fry misled the PAC''.
Rob Wilson, Conservative MP for Reading East, said anyone shown to have misled Parliament without proper justification should resign immediately or be sacked.
He said: ''Thompson's allegations have blown a hole in Lord Patten's argument that the Trust was only responsible for 'strategy' and had no operational involvement in executive payoffs. That in any case is the excuse trotted out by failing boards in many walks of life.
"More fundamentally, Thompson is alleging that Patten has given a false account to the public about his knowledge and involvement of the pay-offs issue for the last several months. It is not good enough for Lord Patten to dismiss Mr Thompson's allegations as 'bizarre'.
"He must urgently shore up confidence in his position and he can only do so by answering each of the specific allegations made by Mark Thompson. The cloud gathering over his position will only darken if he fails to do so.''
In another development, under-fire HR boss Lucy Adams admitted making a mistake in her evidence to the committee.
Adams, who announced last month she was quitting the BBC, initially told MPs she had not seen a note detailing plans for pay-offs to Byford and marketing boss Sharon Baylay – but now admits she helped write it.
She is due before the committee today alongside Patten, his predecessor Sir Michael Lyons, the former chairman of the BBC Executive Board Remuneration Committee Marcus Agius, Thompson and Fry.