A show in which a 16-year-old Muslim schoolboy tries to find a girlfriend and take her home to his strict parents is one of the more provocative in the line-up.

The public service broadcaster, which is legally required to provide educational content, will be spending around pound;4 million of its pound;6m education budget on the internet.

One of its programmes, Get a Life, will feature up to 21 teenagers facing life-changing challenges under the scrutiny of the internet-surfing and television-viewing public.

Channel 4‘s most well-known reality show, Big Brother, faced unprecedented controversy with the racist bullying of Shilpa Shetty, a Bollywood star, earlier this year.

Participants lined up for Get a Life include the Muslim boy from London whose parents have banned him from having a girlfriend, and a 16-year-old Welsh boy who explores his gay identity and hopes to represent the UK in the Eurovision song contest one day.

There is a 19-year-old FE student from London who grew up as “the only brown face” in her family. Over the 15-month course of the show, she will try to find her birth mother in Sri Lanka.

Jeremy Solsby, the show’s producer, emphasised that it was not another Big Brother or The X Factor.

“This is real life,” he said. “There is a huge social responsibility here - we’re not dealing with these people’s lives lightly. There’s no prize at the end.”

Get a Life is produced by SO Television, an independent programme-maker co-founded by late-night television host Graham Norton, and Holler, a digital entertainment agency.

The show will go live on the internet from spring as the participants use online mentors and social networks such as Facebook to work towards their goals. It will begin airing on television in late summer.

Channel 4 insisted it had learnt from the mistakes of Big Brother and would offer support and pastoral care to the show’s participants. They will be allowed to withdraw at any stage.

“It’s not the same as Big Brother, where you’re putting people in an artificial environment,” said Matt Locke, the channel’s education commissioning editor. “We want to represent, not sensationalise their lives.”

John Bangs, head of education for the National Union of Teachers, demanded new guidelines - to be developed in consultation with parents and teachers - for the “brave new world” of cross-platform reality content.

“The potential for insight into youngsters’ lives and aspirations would have great benefits,” he said. “But there is enormous potential to create temporary superstardom, and leave the wreckage of children’s lives behind.”

Chris Keates, general secretary of the NASUWT teachers’ union, who has spoken out against bullying on television in the past, said the presence of television cameras would distort reality.

“This is a very loose interpretation of educational content,” she said. “It sounds like it is designed to sensationalise, not inform and educate.”

But Janey Walker, Channel 4‘s head of education, said they could not compete with the BBC in hard curriculum content, so had chosen to focus on “soft” learning content.

“We’re very aware of the risks for people who are participating,” she said. “The projects are all quite high-risk, and Jeremy will have many sleepless nights in a year of Get a Life.”

Other new Channel 4 shows to air on both the internet and television include Phantasmagoria, which will allow teenagers to develop multiple personalities on social networking sites, and 4Pioneers, in which teen entrepreneurs will develop business ideas without the “back-stabbing and aggression” of programmes such as the BBC’s Dragons’ Den.