Gardam is one of the most challenging, if occasionally opaque, thinkers in television today "My job," he says, "is the management of ambiguity. I'm proud that we're a channel that can do The 1900 House and the Big Brother house. We are not there, as are BBC1 and ITV, to pour the ratings of one show into the next, desperately seeking to distract the audience from looking for something new by offering them yet more of the same."We are not like BBC2, shoring up the bastion of middle-brow, middle England self-assurance. We are probably a more uneven channel; we can lurch from idea to idea, sometimes magnificently, sometimes embarrassingly. But it is in the interweaving of the accessible and the challenging, the funny and the demanding that our critical and our commercial success rests."The poke at BBC2 is a cruel one, as the two channels for years regarded each other as rivals Clearly that is no longer the case. Gardam says: "I think the repositioning of BBC2 will put a certain distance between us Actually, my personal tastes may be more BBC2 It's about the comfort of heritage At 8pm, it's home and leisure."We're different We're very provocative about the contemporary. Our more intellectually ambitious programming is of a piece with our youth market.

Elizabeth is a very interesting example of a programme that had a presenter [Dr David Starkey] who had something intersting to say. It's the first thing I commissioned, actually."Big Brother, he says, was another "hunch" that he backed. I wondered if Gardam, with his background in political broadcasting, was as shocked as I was that the Big Brother household spent not one single second of their weeks together discussing politics? Come to think of it, Channel 4, which at its launch was a highly political channel, doesn't have much to say about politics these days, either."The fact that they never talked about politics in Big Brother tells you much more about how we are now," says Gardam. "The nature of Britain is that it always becomes a Carry On movie, not a French movie. With Big Brother, it became a pantomime."I don't think the lack of political talk was depressing. It tells you about what has happened to politics, that it has become self-referential.

In a way, it's about society coming to terms with the end of the Cold War."Yes, Channel 4 was political when it started in 1982, but it reflected the most ideological decade since the 1930s. I started my career on Nationwide in the Winter of Discontent All that has changed utterly. If Channel 4 still tried to do that, it would be missing the very motors that drive our society."It is social issues, not politics that engage with our viewers. The spine of Channel 4 last year was campaigns on social issues - the mess of the adoption laws; eating disorders, sex education and teenage morality; and Why Doctors Make Mistakes. There's no room any more for default programmes that are there because they are there They don't get watched and they don't get noticed. Better to have specials that hit problems when it really matters."So if there is no room for "default programmes", where does that leave a staple of Channel 4, The Big Breakfast, whose cult status has disappeared and which attracted a low of 300,000 viewers last week?Gardam admits that it is in trouble.

"I think The Big Breakfast is going to have to prove itself in the next year, that it's going to still be there. A programme like that either has to re-make itself or it will die. It's interesting in the modern world how quickly programmes can fade TFI faded very badly in its last year. What has happened with The Big Breakfast is that we are going to completely re-make it. It will have a new editor and we've got a commissioning editor here whose job is just to think about that."On the channel's remit for public service broadcasting, Gardam says: "Our programmes ought to have an impact on the way a society recognises itself and talks about itself.