It’s important that this drama pays tribute to what those guys did.”But isn’t there a danger that viewers will tire of the apparently inexhaustible run of Second World War TV dramas? In the past 18 months alone, ITV1 has given us POW, Island at War, Uncle Adolf and now Colditz. “We gravitate to these stories at a time when we feel we’re not much good at anything any more.”At the same time, Colditz represents the sometimes perverse British love of heroic failure. “We’re drawn to Colditz in the same way that we’re drawn to Dunkirk,” the producer adds “We celebrate notable failure. “We’re attracted to the story of Colditz because it symbolises the British refusal to give in,” Smallwood reckons. “For us, the Second World War is endlessly fascinating,” says Lewis. “It is unarguably the last war where there was an absolutely clear case of right and wrong. It continues to be a huge source for writers who want to examine the age-old themes of honour, valour, duty and evil.

Jason Priestley, star of Beverly Hills 90210, who plays Rhett, a streetwise Canadian inmate, jokes: “I’ve got actor friends who say, ‘If I have to appear in another Second World War drama, I’m going to have to become a conscientious objector.’”So why do commissioning editors keep reaching back for inspiration? The producers of Colditz underline that as the combatants themselves grow older, it is important that we don’t lose touch with their stories. But that generation knew the true meaning of the word ’sacrifice’ Colditz is an impeccably moral story People have died in these uniforms. Any questions?” Willis pipes up: “When I get back to England, would you like a postcard from Buckingham Palace or Trafalgar Square?”, to rousing cheers from all the POWs.It is this defiance that makes Colditz such fertile ground for drama. Swigging from a water bottle between takes, Hardy reckons that it was this overriding sense of duty that distinguished the Allied war effort.

“What’s the biggest sacrifice we have to make these days? To give up the PlayStation? People complain nowadays because they don’t have a bigger telly or the right mobile. They have been brought to Colditz after an abortive attempt to break out of another POW camp. Their fellow escapee, a cunning Glaswegian called Nick McGrade (Damian Lewis, Band of Brothers), has managed to evade capture and returned to Blighty. There, McGrade joins MI9, the secret organisation providing assistance for Allied soldiers attempting to break out of German POW camps.

He also finds himself falling for Jack’s girlfriend, Lizzie, played by Sophia Myles.Werner barks at the new inmates: “I have no doubt that you will try to escape in the future, but you will not succeed If you do try, you’ll be shot You’ll eventually tire of your efforts The sooner, the better – for both of us. On set, two ranks of recently arrived prisoners are lined up to be lectured from a platform in the courtyard by Fritz Werner, the camp’s head of security (played by Rudiger Vogler).The camera zooms in on our two heroes, the unworldly Jack Rose (Tom Hardy from Black Hawk Down), and his straight-down-the-line colleague, Tom Willis (Laurence Fox, The Hole). The men who were in Colditz deserve the greatest respect.”Rewind to last summer, and I am standing in the courtyard of the Colditz that ITV1 has created in a medieval monastery at Kutna Hora, a pretty Czech town about two hours out of Prague. Although the thermometer is touching 32C, a chill runs down my spine as a quartet of Czech extras dressed as Nazi guards march past me, their Alsatians snarling and barely restrained by their metal leashes. I am stationed at the edge of the main courtyard – a broiling cauldron enclosed by walls five storeys high – in this recreation of the dreaded Nazi prison.