Former director general of the BBC Greg Dyke says the Corporation is the envy of the world - but faces an uncertain future because of "hostile politicians".

He said the broadcaster also faced opposition from commercial interests and parts of the press, who are out to "destroy it for their own financial reasons".

And he warned that Britain would be a "much poorer place without the BBC".

Speaking at a discussion about the future of the BBC held at the British Academy in central London, Mr Dyke argued that the Corporation plays a crucial role in British life.

He said: "Go around the world and talk about the BBC and in so many countries people are in awe of it. It is one of the world's great brands."

He said that as chairman of the FA, he turned to the BBC to reinvigorate the fledgling FA Cup football tournament.

He said: "We used their brand, their integrity, their marketing power to help rebuild the FA Cup.

"The result after one season was brilliant.

"And yet we have politicians who don't understand the BBC, what it has achieved, and want to see it diminished largely for political reasons."

He accused some politicians of wanting to undermine the BBC because it challenges their view of the world.

He said: "Those successes at the BBC over so many years undermines their fundamental belief that there is only one way of organising society.

"My greatest fear is that one day they will win, and we will wake up and discover that the BBC has gone, and it's only then that we understand what it delivered.

"There is no other country in the world who would even have this debate."

He also singled out the BBC's biggest rival, ITV, for criticism. ITV has accused the BBC of breaking promises that it would not chase ratings.

Mr Dyke said: "ITV should be ashamed of their current position."

"ITV today is just being commercially opportunistic," he added.

The future of the BBC is up for discussion as part of the charter review.

Musician Brian Eno also spoke up for the BBC and lashed out at commercial TV - which he said he "hates".

Although he admitted he has not owned a television since the early 1980s.

The former Roxy Music member, who was one of a panel of four discussing the BBC's future, said he wants broadcasting to become "more elitist".

He told the meeting: "I should confess at this point that I don't even have a television, and I haven't had one since the early 1980s, because actually what I love is radio and in fact I love BBC radio so much I frequently write to them like some mad fan."

He said TV should become more like radio and play to people's niche interests.

He said: "My vision for the future of television is to be more like radio. I find radio much more serious, much more engaging and much less entertaining.

"I'm bloody sick of being entertained.

"I don't want to be entertained, I want to be provoked, I want something to think about. And between Radio 4, the World Service and Radio 6, there is a lot to think about.

"I want to make television, I suppose, even more elitist really. Even more catering to niche people like me."

And he took a swipe at commercial broadcasters, which he said he "can't bear", and warned against privatising parts of the BBC and leaving a rump.

He said: "It'll turn out that all the good bits of the BBC, all the bits we want, will disappear or get hived off because they are profitable, and then get turned into c**p.

"I suppose I don't have a television because I so hate commercial television. I can't bear it. It depresses me and it makes me want to shoot myself to think people spend their lives making this stuff."

During a lengthy discussion about the future of the public service broadcaster, Mr Dyke said there was scope for the BBC to expand its output on local news.

But he said the Corporation has shied away from putting these arguments forward because it is "a bit on the back foot and a bit scared".

He told the audience of several dozen people that in an era when many local papers are closing, there is a strong case for the BBC to be boosting its local news coverage.

He said: "There are areas that the BBC should be expanding into because in a democratic society that is necessary.

"And it's not happening. And because the BBC is a bit on the back foot and a bit scared it's not actually going out and saying 'this is what we are going to do'."