Ainsworth: "Appointment of Greg Dyke controversial enough"

Gavyn Davies, currently BBC vice-chairman, is known to have Labour leanings and is a close friend of Gordon Brown - while other candidates also have clear political links.

If Goldman Sachs economist Davies did become chairman, under previous precedent he would be given a Conservative-leaning deputy.

Now the BBC vice-chairmanship will be advertised, as the chairmanship has been, for the first time - with the successful candidate chosen on merit rather than political leaning.

Davies: Known to have Labour links

Shadow culture secretary Peter Ainsworth told BBC News Online: "It would be detrimental to the BBC and its obligations of impartiality if both chairman and vice-chairman were seen to be supporters of the government of the day.

'Controversial'

"This is an appointment made by the DCMS and ratified by the prime minister - nobody's fooled by talk of 'arm's length'.

"The appointment of Greg Dyke was controversial enough - but if these appointment procedures ended up with the three top men at the BBC of one political persuasion, it's the BBC that would suffer."

Jowell: Will stand by Nolan rules

But a DCMS spokeswoman confirmed on Tuesday that Culture Secretary Tessa Jowell would follow the so-called Nolan rules whoever becomes chairman.

Interviewing for the post of BBC chairman begins on Tuesday.

The BBC chairman shortlist consists of six candidates: Gavyn Davies, David Dimbleby, Michael Grade, Baroness Jay of Paddington, John Ashworth and Dame Pauline Neville-Jones.