A bit of television escapism (if the contestants can get past razor wire)

After enduring weeks watching contestants fight to remain in Channel 4's Big Brother household, Britain's army of couch potatoes is about to be subjected to the opposite - 10 people trying to break out of a purpose-built prison.

After enduring weeks watching contestants fight to remain in Channel 4's Big Brother household, Britain's army of couch potatoes is about to be subjected to the opposite - 10 people trying to break out of a purpose-built prison.

To capitalise on the popularity of 24-hour invasive television, Channel 5 has come up with Jailbreak, in which "prisoners" will compete to escape and win £100,000.

Yesterday journalists were ferried by helicopter to the hitherto secret site of the set, a mock-prison featuring security systems designed by experts for real jails. It is a £2.5m investment, a corrugated-steel compound with dormitories for men and women, searchlights and 18ft fences topped with razor wire. And cameras, everywhere cameras.

Depending on your view, it is a new high in television innovation or the bottom of the voyeuristic barrel. But it is likely to be compulsive. There will be real guards from the Scottish prison service, a real governor, a prison psychiatrist and a real prison chef. And, in Craig Charles of Red Dwarf fame, it will have a presenter who has been in prison.

In 1994 he was held on remand in Wandsworth prison, south London, for 100 days on rape charges before being acquitted. Inevitably, as he was unveiled as the presenter in a windswept field outside Cuffley, Hertfordshire, he was asked if his experience would stand him in good stead. "Look," he said. "They've asked me to front this show because I'm an experienced television presenter, not because I've been in prison." But he did admit that during the show's three-week run, beginning on Tuesday, there were likely to be "celebrity ex-cons" as commentators.

Channel 5's controller of features and arts, Michael Attwell, said: "This is a radically different programme. It is likely to turn out very different from the other observational and reality programmes ... It is genuinely original and experimental television."

The 10 contestants, aged 20 to 60, who will only be told on Sunday that they have been chosen, have had psychological profiling to ensure they can take the stresses and strains of prison life. They will be in two dormitories. Their every step and breath will be recorded. They will be required to work for up to eight hours a day in the prison workshop and garden while looking for ways to escape, picking up clues and hints and looking for chinks in the security.

They will be hard-pressed to find any. The programme makers have gathered together some of the most advanced security equipment in the world, including iris scanners and thumb-print recognition systems to prevent intruders getting in or out. There are three fences and a variety of alarm systems triggered by movement and noise.

The guards - up to 10 at any one time - will have seven surveillance cameras, while the television producers will have 35. They are not allowed to tip off the guards but, in the only serious departure from a prison regime, viewers can e-mail prisoners with suggestions and ideas.

Each prisoner is allowed to receive five e-mails a day from viewers. If a viewer sends in advice that results in an inmate escaping, he or she will be given a £10,000 prize. Other prizes include a holiday to Alcatraz, the former island prison off San Francisco.

Jim Heyes, "governor" of the Jailbreak prison, said: "It's quite realistic in there - have you felt those mattresses?" Mr Heyes, a penal consultant, has been in the jail service for 28 years, acting as governor at several prisons, including Gartree in Leicestershire, where his wards included the train robber Buster Edwards. He knew very well that the Jaibreak prison was nothing like a real one but, with the other professionals on board, said that the programme was unadulterated entertainment.

So too did the prison psychiatrist, Sandra Scott, a senior registrar at the Maudsley Hospital, south London. She said: "At the end of the day, it's just a game show. People shouldn't take it too seriously but, given that these shows are going to be made anyway, I think it is better that psychiatrists and psychologists get involved to ensure no one suffers harm because of them."

She said that some contestants had already stated a "Nasty Nick" aim of winning by any means necessary. Nick Bateman, the man whose Machiavellian scheming in Big Brother fascinated viewers, is thought to have been invited to participate in some way on the outside.

So will it be seriously tough inside? Mr Heyes said: "It's up to me to see they get treated firmly but fairly. But they shouldn't worry too much. I'm just a pussycat really."