The chair of the BBC Trust, Lord Patten, is resigning from his position immediately on health grounds after undergoing major heart surgery.
The former Conservative minister was admitted to hospital at the end of April with severe chest pains before having a combination of bypass surgery and an angioplasty.
In a statement Lord Patten said his doctors had advised him to "reduce the range of roles" he takes on.
On stepping down from the BBC Trust, he said:
"This is a position that requires and has received from me 100 per cent commitment, and has been my priority at all times.
"It would not be fair to my family to continue as before; and equally it would not be fair to the BBC and those it serves not to be able to give that commitment which the role demands."
BBC bosses - past and present - argued over who knew what and when about huge payoffs to senior staff as they gave evidence to MPs today.Read the full story ›
Seven BBC executives - past and present - argued over who knew what and when about huge pay-offs to senior staff, as they appeared in front of the Public Accounts Committee today.
Former director-general Mark Thompson, was forced to deny a charge that the BBC had "lost the plot" when it agreed a pay-off of almost £1 million to his former deputy, Mark Byford.
ITV News' UK editor Lucy Manning reports.
The chair of the Public Accounts Committee Margaret Hodge has described the questioning of BBC executives as an "unedifying occasion which can only damage the standing and the reputation of the BBC".
Current and former BBC executives were questioned by members of the committee today in the wake of controversy over large payoffs to corporation executives.
Ms Hodge said: "At best what we've seen is incompetence, lack of central control, a failure to communicate for a broadcaster whose job is communicating.
"At worst we may have seen people covering their backs by being less than open. That is not good."
The chairman of the BBC Trust said there was "a cultural issue" of high pay that had to be dealt with and he apologised for.
Lord Patten said:
The best cultural director in the world, Neil MacGregor, got £180,000 a year for running the British Museum. How many people at the BBC get paid more than that and how can we justify that?
Licence fee payers will be "dismayed" by the evidence given by BBC executives past and present about massive payoffs to staff, a senior Labour MP warned.
Harriet Harman MP, shadow culture secretary, said: “Clearly the interests of the licence fee payers were not properly protected and there was a failure of governance.
"The Charter renewal process, and the debate around it, will be the opportunity to re-examine those governance issues."
Committee member Chris Heaton-Harris compared the meeting to a fairground game, saying it was "the most bizarre game of whack-a-mole I've ever seen in my life, where you hit one fact down and it throws up other questions".
Turning to the witnesses, he said: "I just wonder if one of you would like to take responsibility for this?"
Committee chair Margaret Hodge told Sir Michael Lyons, former chairman of the BBC Trust: "You could have done it for less, that's the whole premise for us."
He replied: "I have heard your message but I am not personally convinced that's the case. My judgment tends towards that of the Director General here."
He said that it was a way of doing things that prevented "disruption" to BBC services and projects that were in the pipeline.
The former Director General of the BBC told the Commons Public Accounts Committee that he believed Mark Byford's severance package represented "value for money".
Mark Thompson also said he stood by his claim that the committee had been misled when they were told the Trust had been "kept in the dark" about severance packages.
The director of the BBC Trust said he was not "closely involved" in the preparation of a note on about the Byford payment.
Nicholas Kroll, conceded the payoff was "unquestionably a large figure" but a matter for the remuneration committee and not the trust.
In response, Jackie Doyle-Price MP told him the protection of licence-fee payer's money was "a matter for the trust".
Ms Hodge told Mr Kroll that the "the job of the trust is to protect the licence fee payers' interests".
She added: "There is not one person around the table who can understand why there was no challenge from you".