Jowell: Recommended choice of Davies to Queen

"The BBC is a magnificent and precious organisation," he said.

But the appointment has been criticised because of Mr Davies' strong links to Labour - he is a close friend of Chancellor Gordon Brown and his wife is Mr Brown's private secretary.

Mr Davies insisted viewers could be confident of unbiased coverage.

"It is very difficult to find people who can function in jobs like these without those people having previous connections politically," he said.

"As long as the appointments process is transparent and there is a broad mix of political views among the governors of the BBC, I think the public can feel confident that impartiality and independence are just as important to me as they have been to previous incumbents."

Mr Davies said he had now resigned his membership of the Labour Party.

Tim Yeo: BBC "needs to salvage reputation for impartiality"

But the fact that both the chairman and director general Greg Dyke have known Labour ties had led to criticism from Conservatives.

They are now calling for a Tory vice-chairman to be appointed in line with past convention that a deputy has the opposite political leanings of the chairman.

Shadow culture secretary Tim Yeo said the chairman and director general had never before been "prominent" supporters of the same political party.

"The only way for the BBC to salvage their reputation for political impartiality would be for them to appoint an identifiable Conservative vice-chairman," he said.

Culture Secretary Tessa Jowell dismissed allegations of "cronyism", saying the new process of using an independent panel to appoint the chairman was "a massive step forward".

"The old way, with politicians making decisions in secret, is gone for good," she said.

Ms Jowell says she hopes to appoint a new vice-chairman within three months - but again the appointment would be made by the independent panel and on merit rather than political background.

It is understood Prime Minister Tony Blair telephoned new Conservative leader Iain Duncan Smith personally to give him the disappointing news for the Tories.

David Dimbleby was also on the six-strong shortlist

The BBC board of governors said Mr Davies would get their full support.

"In his eight months as vice chairman, we have all been impressed by Gavyn's understanding of the BBC and the communication industry," they said in a statement.

"We share a commitment to uphold the BBC's political and editorial independence. We are absolutely confident that Gavyn will be at the forefront of protecting that independence over the next five years."

An independent panel interviewed the six shortlisted candidates for the chairmanship last week, under the newly-established anti-corruption Nolan rules.

On the shortlist alongside Davies were broadcaster David Dimbleby, media owner Michael Grade, former Labour politician Baroness Jay of Paddington, scientist John Ashworth and BBC governor Dame Pauline Neville-Jones.

It is understood Davies was the only candidate recommended to ministers by the panel, which considered his political affiliations.

The panel was headed by Nicholas Kroll, acting permanent secretary at the Department for Culture, Media and Sport, and included Reuters chairman Sir Christopher Hogg, zoologist professor Sir Brian Follett and Liz Forgan, former managing director of BBC network radio.

The final choice was made by Mrs Jowell, with the decision ratified by the prime minister. The appointment was confirmed by the Queen after a meeting of the Privy Council.