ONE CHANCE (12A, 103 mins) *** Starring James Corden, Julie Walters, Colm Meaney, Mackenzie Crook, Jemima Rooper, Alexandra Roach, Kathryn Drysdale, Valeria Bilello. Director: David Frankel

The story of an overweight, accident-prone, opera obsessive might not read as silver screen magic, but it looks like the team behind One Chance has struck gold in depicting the tale of Britain’s Got Talent winner Paul Potts.

James Corden dons the gnarly teeth to play Potts, a shy, bumbling man, who has spent years being bullied and lives with his parents in Port Talbot. He earns his living working in Carphone Warehouse with his best mate (Crook) but dreams of becoming an opera singer and listens to classical music every moment he can, something his mother (Walters) encourages and his dad (Meaney) bemoans.

After meeting Julie-Ann (Roach,) a girl he’s been chatting to for a year online, she persuades him to take his first tentative steps towards realising his ambition by taking part in a local talent show.

After silencing a heckling crowd with his stunning voice, Paul uses the winnings to enrol on a course in Venice. There he meets the beautiful singer Alessandra (Bilello) and earns the opportunity to sing in front of Pavarotti. But when it comes to the big day, nerves get the better of him, he chokes and the big man tells him he’ll never make it.

So Potts returns to Wales, wins over Julie-Ann, who he’s neglected, and plods along in life, overcoming a host of obstacles (mainly health-related) before applying to take part in Simon Cowell’s talent show.

The movie is not without faults.

There are predictably saccharine moments, although these are kept to a minimum in the hands of The Devil Wears Prada and Marley And Me director David Frankel. For instance, the film doesn’t end with Potts being voted the Britain’s Got Talent winner. Those scenes (which interweave the original footage of the judges with Corden standing on stage) simply play out as part of the bigger story.

There are strong performances, particularly from Corden, who refrains from gurning his way through the film, and an endearing Roach, who came to prominence as the young Margaret Thatcher in The Iron Lady.

The film isn’t life-changing but it is feel-good, even if you do feel a little cheated of enjoying a big finale like Billy Elliot and The Full Monty managed.

Just as the sceptics among us wrongly judged Potts, they should be mindful of doing the same with this movie. After all, it’s the story of a championing underdog, and that’s always something to applaud.