Writer and director Armando Iannucci will turn his attention to the future of broadcasting at a TV industry get-together tonight.

The satirist will deliver the James MacTaggart Memorial Lecture, the keynote address at the 40th Guardian Edinburgh International Television Festival.

Oscar and Emmy-nominated Iannucci, who directed the cult hit I'm Alan Partridge and political comedies The Thick Of It and Veep, will discuss the theme of what television channels are for, as well as the future of BBC funding, government interference and the changing dynamic of how the public view TV.

Speaking ahead of the festival, Danny Cohen, director of BBC television, highlighted the importance of the "public's voice".

He said: "Don't know if you've read all of the Government green paper but we welcome this debate about the BBC, it should happen every few years, but the key to it should be about what the public want, it shouldn't just be about what opinion-formers want, it should be talking to the public, what the public want from the BBC, how can a strong BBC be used to benefit Britain and what do they want from it.

"I think that need now for the public's voice in this debate to be paramount is very important."

His comments come as the Culture, Media and Sport Committee prepares to scrutinise the BBC's charter review, which sets the parameters within which the corporation operates.

Unveiling the green paper last month, Culture Secretary John Whittingdale said the review of the BBC's royal charter would look at whether the BBC should continue to be "all things to all people" or have a more "precisely targeted" mission.

Mr Whittingdale will be interviewed at the festival today, and Mr Cohen said they will "listen carefully" to what he says.

He added: "I don't think politicians want to choose what is on Saturday nights and nor should they.

"People in TV should make those choices and the public vote with their remote controls whether they like it or not."

Mr Cohen said he does not know what Mr Whittingdale will say but said "in general he's a strong supporter of the creative industries".

Last month, Mr Whittingdale sparked speculation the BBC may be told to cut back on popular programming which competes with shows available on commercial broadcasters or to reduce its online presence, and he raised questions about the future of the licence fee, suggesting that the BBC could switch to a subscription service in the long-run.

Commenting on the feeling between the BBC and the Government going into Edinburgh, Mr Cohen said they have the "best settlement" they believe they could get in "challenging circumstances".

He said there were "robust" negotiations, adding: "I think we want to be open, we want to hear what they have to say, but we also clearly want to defend the BBC's purpose and importance of the licence fee and the importance of it to the creative industries, and why that matters."

He also spoke up for the BBC's entertainment output.

"I'm going to make a strong defence whenever I can at Edinburgh about entertainment on the BBC. I don't know why personally entertainment has become a dirty word in the context of the BBC," he said.

Commenting on the deal that gave the BBC responsibility for funding free TV licences for the over-75s, Mr Cohen said: "We weren't expecting to take on the costs of the over-75s but we know this is a tough time and we have to take our share of that."

When he was announced as the speaker in May, Iannucci said: "In the current climate where no one knows what the hell is going to happen to TV schedules, revenues, watching habits, funding, quality control, the BBC, investment, licence fees, charters, and government interference, I'm terribly excited to be asked to join the debate in this, perhaps our most spectacularly clueless year.

"Nobody knows anything, and in my MacTaggart Lecture I'm sure that will become abundantly clear. I'll do my very best, though, to show why TV still matters."

Previous MacTaggart Lecture speakers have included Kevin Spacey, James Murdoch, Jeremy Paxman, Greg Dyke, Dennis Potter and Eric Schmidt.

The festival runs from August 26 to 28.