Director Peter Cattaneo, best-known for The Full Monty, has chosen a fine cast for this sometimes hilarious, sometimes sad character-based ensemble prison comedy.

The story follows loveable Irish rogue Jimmy (James Nesbitt) who is imprisoned, with his partner-in-crime Rudy, after a bungled robbery. Tormented by the prison's sadistic Chief of Security, in and out of solitary confinement, and with five years behind bars left to go, he jumps at the opportunity to put on a prison musical because it will offer the chance to make a break.

However, when he starts falling for the girl (Olivia Williams) at his compulsory anger-management class, his sense of urgency to escape starts receding.

The story in the cold light of day, stretches credibility to breaking point, in particular that a gorgeous girl like Olivia Williams would be casually wondering around the jail of sex-starved criminals, or the idea that all cons have such soft underbellies. And would anyone conceive of such a hair-brained escape, particularly when starring in the musical?

But realism is perhaps not the point. This is a family comedy with a host of wonderfully observed prison characters, in particular Christopher Plummer's eccentric Governor and Bill Nighy's gentlemanly con. Timothy Spall, as the victimised inmate, adds a more tragic note. But this doesn't seem out of place in a film that is less raucous in tone than The Full Monty, and similarly blends pathos with humour.