Celebrities see what life inside is really like in 'Banged Up'

What do EastEnders actor Sid Owen, Gogglebox star Marcus Luther and Conservative MP Johnny Mercer have in common?

They are among the unlikely group of seven famous faces at the centre of this fascinating four-part constructed documentary series.

Cameras will follow them while they are locked up for eight days in decommissioned HMP Shrewsbury, to find out what life is really like behind bars.

The celebrity inmates will rub shoulders with a variety of real ex-criminals, including those who have served long sentences for serious crimes.

All of them are now reformed and have agreed to re-enter prison specifically for this series, for one very important reason. Their famous cellmates, who will all be living by current UK prison rules, will have the opportunity to talk to them about their experiences in jail, as well as their former crimes, to get a true assessment of what impact the system had on them – for good or ill.

The estate will be run by a former prison governor with 20 years’ experience in some of the UK’s toughest prisons, while everyone is overseen by former prison officers.

EastEnders actor Sid Owen is first to arrive in this opener. Both of his brothers and his dad, who was a bank robber, spent long stints behind bars.

He wants to see what life was like from their perspective and experience the conditions he could have ended up in, had acting not changed his life.

However, being stripped of his home comforts and locked in a cell for more than 13 hours a day is harder than Sid ever expected, and forces him to take drastic action.

Meanwhile, Conservative MP Johnny Mercer freely admits that he knows very little about the prison system. Growing up, he was a choirboy who went to a posh school.

He wants to find out for himself whether prison works. When he arrives, he meets Kevin, a convicted contract killer who describes how he used to run people over and why he believes his criminality is due to the fact that he didn’t have a father.

There’s also Tony, who used to take anything that didn’t belong to him. Pushed to his limits, and doing things he never thought possible, Johnny begins to question what the prison system is really out to do: punish or rehabilitate?

Marcus Luther, of Gogglebox fame, says he grew up in the ‘hood’, the same ‘ends’ as most of the people who commit crimes. But he made a choice not to break the law.

So why do these guys keep committing the same “dumb old crimes” that land them banged up? He hopes to find the answer during his stay at Shrewsbury.

Marcus steps onto the wing full of confidence, which is immediately dented when he’s surrounded by a gang of inmates who want him to ‘G check’ (bully) another prisoner.

Marcus’s response could see his card marked but also leave him open to retaliation. It will remain to be seen whether he stays true to himself or falls in line with the top dogs.