Dorothy Byrne: Why we want young viewers at Channel 4

'I make no apology for aiming this programme at the under-25s; it's vital we engage them'

It was a delicious moment. Our Channel 4 mole inside Labour Party headquarters had just been given responsibility for accrediting the journalists attending press conferences there. Who would not have been tempted to cause a bit of mischief by denying passes to some of our rivals at the BBC and ITV?

But when we placed moles in the three main parties' headquarters, some time before the election, we decided that all must carry out their party functions to the letter. So our Labour mole, Zoe Spyropoulos, granted the passes ­ even to John Sweeney of Radio 5 Live, who, somewhat inconveniently, knew her and might wonder what she was doing there as a Labour meeter and greeter.

There were other strange moments in the making of Party Crashers.But enough of this fun. What was our justification for broadcasting this programme? Well, our video diarists found an obsession with image, a terror of error and blatant attempts to manipulate and control television, radio and national newspaper stories. Our Labour mole, Zoe, said she felt we hadn't uncovered anything important, but I must beg to differ. We demonstrated, from the inside, how major political parties attempt to control the flow of information to the public in a general election. That's worth telling the voters.

Zoe also felt that the programme was unbalanced because our three moles had different jobs in their respective parties. But what interested me as the commissioning editor was that all three were essentially telling me the same story of party manipulation of image and news.

The programme formed part of Channel 4's coverage of the election campaign under the boldest of titles, "Politics Isn't Working", a series of programmes in which we've examined why politics isn't connecting with the electorate. In The Independent last week, Zoe criticised Channel 4 for aiming programmes at young viewers. I make no apology for aiming this programme at young viewers. When half of potential voters under 25 say they don't plan to vote, I think it's vital that we try to engage them in some way. One of the political parties, when berating me for placing our young mole within its organisation, said: "The BBC would never have done a thing like this", and I took that as a compliment.

Zoe offered a sweeping condemnation of what she sees as Channel 4's all-encompassing commercialisation. She feels disillusioned when sitting in meetings with commissioning editors, because she believes they are interested only in chasing ratings and winning advertiser-friendly audiences. Well, we do want lots of people to watch our programmes and we want young viewers ­ because we need to succeed in a competitive television environment. It's to the credit of commissioning editors other than me that we do this so successfully. Take, for example, Big Brother and Graham Norton ­ commercially successful, creatively ingenious and Bafta-winners both.

Zoe expresses regret for her lack of loyalty to her friends in Hardcash Productions, the independent production company for which she was working while making Party Crashers. She even praises some fine foreign investigations that it is responsible for ­ programmes undercover in North Korea, Afghanistan and Kosovo, in which those involved risked their lives. It's ironic that all these films are broadcast on Channel 4. It's precisely because of the success of programmes such as Big Brother that we can broadcast "non-profit" films such as the "Politics Isn't Working" season and Hardcash's foreign investigations in the heart of prime time.

Zoe fears that Channel 4 has somehow become "lost". But I say we are currently very confident of our direction. Just look at this year's Bafta-winners to get a sense of our range and depth. I don't think Zoe should worry so much.

Dorothy Byrne is commissioning editor, news and current affairs, Channel 4