(M) ***

Director: David Frankel.

Cast: James Corden, Alexandra Roach, Mackenzie Crook, Colm Meaney, Julie Walters.

SO this is how all-pervasive reality TV has become.

It fills our screens at home, the people it "discovers" bombard us on the airwaves, in magazines and on the internet, and now we're getting movies about its "stars".

A few months back there was the puff piece-masquerading-as-a documentary about X Factor participants One Direction. This week it's this quaint little dramedy about Britain's Got Talent winner Paul Potts.

Not surprisingly, both of these movies are produced by Simon Cowell - the man who created X Factor and Britain's Got Talent. He also features in both films. His quest for global domination continues.

But let's attempt to put the cynicism aside for a minute and look at the life and times of Potts.

As an overweight child born with "a big voice", Potts was bullied as he grew up, but nothing could shake his love of opera and his desire to be a tenor.

One Chance follows him on his "journey" (to use reality TV's favourite word) from humble phone salesman to opera student in Venice to married man down on his luck to Britain's Got Talent contestant.

It's a tale that is full of heart and pathos, led by an amiable performance from Corden, who brings a level of depth and integrity to the role that will surprise anyone who saw him in the 2009 flop Lesbian Vampire Killers.

It's also a tale that tends to feel like a 90-minute version of one of those 30-second sob stories they show before the contestant walks on stage to perform on whichever reality talent quest they're taking part in - the ones where they talk about the health issues/family tragedies/heartbreaking setbacks that forced them to give up their dream until they decided they would go on whichever reality talent quest they're taking part in and give that dream one last shot.

In Potts' case, there are plenty of obstacles in his way and audiences will either find his triumphs over adversity charmingly sweet or sickeningly saccharine. Whichever way you fall, the film is undeniably moving in places. Sure it's manipulative - as to be expected from the guy who directed Marley & Me - but Potts' breakthrough moment at the movie's conclusion still resonates, making it easy to see why it drew 118 million hits on YouTube.

The story takes some rather large liberties with Potts' life, such as omitting much of his amateur opera career, an Italian tour with the Royal Philharmonic Orchestra, and his stint as a city councillor, presumably because they don't fly with the film's portrayal of Potts as a despondent, bullied, put-upon underdog with the voice of a solidly built angel.

But there is a lot of emotion and empathy drawn from what remains, and the film will appeal, particularly to those who love such British underdog stories as The Full Monty, Brassed Off and Billy Elliot.

A quintessentially British sense of humour is also prevalent, with Corden getting some good laughs from the gentle material. Roach is also great as Potts' partner Julie, while the pairing of Meaney and Walters as his parents is a successful one, even if the roles do feel stereotypical. Crook gets a few good lines as well, which makes his presence as the comic relief character welcome rather than distracting.

It's a predictable story, even if you've never heard of Potts. The desire or need to have a villain in the film leads to an awkward bullying subplot that resolves itself entirely as expected and you'll pick most of the key moments coming along the way.

For anyone looking for a sweet inoffensive charmer, this could well be their movie of the year. It does its blend of heart and humour with few hiccups along the way.

For those who are a tad more cynical and who like a bit more edge or depth to their films, it would be best to stay away.