Thirty-four, the recipient of a double first from Oxford and engaged to the glamorous intellectual Noreena Hertz, Danny Cohen is the boy wonder of British television.

A rapid rise took him to the controllership of BBC Three last year, and now, with a relaunch pending next Tuesday, he will have to show that he can deliver on the ample promise.

Mr Cohen’s aim is to take the channel, aimed at 16-to-34-year-olds, and “warm it up”, which is why he has dropped Anthea Turner, brought in Lily Allen, shed the old grey-on-blue logo in favour of a liquid pink one and put on fewer parenting programmes to attract a core audience “closer to the early 20s”.

Yet the challenge is somewhat greater. First, the idea is to “integrate the TV and web world” – a test, in other words, to see whether the much-vaunted online-television convergence can resonate.

And, secondly, Mr Cohen has to prove that BBC Three - with its £83 million-a-year budget – deserves to exist. With an audience share of 1 per cent in digital homes, airing un-BBC-like programmes with titles such as Me and My Man Breasts and trampling all over Channel 4’s turf, it is not clear that the network is successful or distinctive.

“The idea that young licence fee payers don’t deserve a channel that is aimed at them is ridiculous,” Mr Cohen says. He is modest and low-key, although obviously intellectually confident. “I’m doing the job that BBC Three should be doing. There are lots of programmes on Channel 4 that wouldn’t be right for BBC Three,” he says, noting that C4’s audience is broader and, at times, older.

The audience share statistics are misleading, apparently. “In the hours we broadcast, from 7 [pm] to 3 or 4-ish in the morning, our share was 2.2 per cent of individuals and 3.3 per cent of 16-to-34-year-olds last year. In the first week of 2008, we reached 16 million people – not bad for a digital channel.”

Mr Cohen wants to extend the channel’s hours into the afternoon, too, although a lack of digital capacity on Freeview makes it unclear how that will happen.

His channel relies in part on East-Endersrepeats at 10pm. He says that it is “massively useful to have a show that reliably brings big audiences” – obviously – and it gives him a slot at 10.30 to promote a new programme with an inherited audience of 700,000 to 800,000, big for a digital channel.

He steers a careful course on the controversial programmes, arguing that “behind the titles there were well-made and thoughtful documentaries”, although he says that “we’ll look at titles on a case-by-case basis” – code, it appears, for saying that he will be a bit more careful in the future.

Unsurprisingly, he defends the channel by highlighting some high-quality shows and its high level of original production, which, given the budget available, is the least that it should be doing. “There’s rarely anything on BBC Three that wouldn’t be on Today or Newsnight, just in a different form,” he says, highlighting Kizzy: Mum at 14, a documentary about teenage pregnancy that “reached two million people” across several showings.

The new season contains a familiar streak of populism. Find Me the Face features two modelling scouts hitting the streets to locate talent. Coming of Age is a sixth-form sitcom written by the 19-year-old Tim Dawson, and the quality ranges from the journalist Dawn Porter removing her clothes in Central London to a serious programme, Making the Clothes I Wear, about how fashion items are made in the developing world.

The digital strategy begins with BBC Three being streamed live on the internet and, in a neat touch, getting viewers to act as continuity announcers, based on the clips they submit. On Lily Allen and Friends on Tuesday nights, the singer and presenter wants people to sign up to become her friend in a BBC-created social network site. Friends can appear in the audience, submit questions to guests and vote on which of two unsigned bands should perform.

Will it be popular? “I’m encouraged by the early signs,” Mr Cohen says. However, in an effort to manage expectations, he adds: “I’m not expecting a massive change in audience share,” as he talks broadly about the impact on the overall schedule.

However, if television and online integration is going to work, Allen, 22, is the right kind of star to promote it on the screen and Mr Cohen is the right kind of executive to give it a try. If the youth-orientated channel has a long-term future, it is in their hands.

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