Plans to slash the BBC’s radio, TV and website services - including the Birmingham-based Asian Network - are expected when the corporation unveils what is being billed as the biggest shake-up its 88-year history.

The broadcaster is reportedly planning to close down digital stations BBC 6 Music and the Asian Network, as well as reducing the number of its web pages by half and slashing spending on imported programmes.

Director general Mark Thompson will outline his strategic review amid growing opposition from the stations’ fans and repeated warnings from unions of industrial action.

According to leaked details published last week, Mr Thompson will announce that the BBC has become too large and must downsize its operations to give greater opportunities to commercial rivals.

Writing in The Guardian, he said the BBC “should not attempt to do everything” and “should leave space for others”.

Mr Thompson added: “It must listen to legitimate concerns from commercial media players more carefully than it has in the past, and act sooner to meet them.

“It needs the confidence and clarity to stop as well as to start doing things.”

The review comes amid debate over the future of the BBC’s £3.6 billion annual funding from the licence fee, and recent long-running criticism of some of the salaries paid to its stars and executives.

Music legend David Bowie has joined efforts to back 6 Music, which boasts has 695,000 listeners and a DJ line-up that includes Jarvis Cocker and Lauren Laverne.

He said: “6 Music keeps the spirit of broadcasters like John Peel alive and for new artists to lose this station would be a great shame.”

Whispers about the demise of the station has already led to a Facebook campaign opposing the axe with more than 60,000 supporters.

Press reports have also said the BBC will cut its online staff by a quarter. and dispose of BBC Worldwide’s UK magazine titles.

Gerry Morrissey, general secretary of the broadcasting workers union Bectu, said he believed any cuts would be politically motivated.

“It is obvious that the BBC is being bounced by its competitors and by the political climate ahead of the upcoming general election,” he said.

“These proposals are unnecessary and it is not acceptable for the BBC to be offering up services and jobs as some kind of sacrifice ahead of the general election.”

Jeremy Dear, general secretary of the National Union of Journalists, added: “Public pressure can help persuade the BBC to put its viewers and listeners first, rather than allowing the corporate media barons to have their way and begin dismantling a vital national service.

“These plans smack of an attempt to appease commercial and political interests. Hard-working staff shouldn’t be used as a political football and we will fight any compulsory redundancies.”