Eddie Izzard and David Tennant were among around 40 actors and entertainers who signed a public letter to say opposition politicians were "attacking the BBC to serve the interests of its commercial rivals".
The letter claimed the Conservative party's position "threatens to devalue not just the BBC itself, but our culture as a whole".
However, speaking to the Radio Times in an interview published today, Cameron claims he is "probably the most pro-BBC Conservative leader there's ever been".
The Tory leader insisted he would never do anything to put the BBC at risk.
He said: "I worked at ITV (in public relations) for seven years and you learn to respect the incredibly important role the BBC plays. Competitors like the BBC because you're competing up here on quality rather than down here on price."
After admitting to listening BBC 6 Music, Cameron said the closure of the station was an issue for the public sector broadcaster.
However, he said the BBC had overreached on magazines, its website and Lonely Planet (which it accquired in 2007) and so it probably needed "to retrench a bit to focus on what matters most".
He added: "So while I might like listening to Radio 6 because it's my sort of music, you can't do everything."
While the Conservatives have invested in social media in the run-up to the election as a way of engaging new voters, Cameron concedes he does not 'get' social media.
In the interview he also admits he is not on Facebook or Twitter and while he realises the opportunity politically, personally he does not want "to be 'poked' or whatever it is".