I want the BBC to be a mass market public service broadcaster still funded by the licence fee... and the licence fee is more durable than many people in the commercial sector believe.

Over the last decade, - economists seemed to share a broad consensus about economic policy, with the old splits between monetarists and Keynesians apparently being settled by events. But the Great Recession of the last two years has changed everything.

Without the BBC, the proliferation of television and radio channels by the private sector would simply result in more and more channels, with tiny audiences, all seeking to do the same thing. The future would be one of fragmentation - fragmentation without either plurality or diversity.

The BBC should not have a cheerleader. It should have somebody who runs the organisation in the interests of the public and that should be a chairman.

As long as the appointment 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.

I want the BBC to be a mass market public service broadcaster still funded by the licence fee... and the licence fee is more durable than many people in the commercial sector believe.

There is an honourable tradition in British public life that those charged with authority at the top of an organisation should accept responsibility for what happens in that organisation. I am therefore writing to the prime minister today to tender my resignation as chairman of the BBC.