Film review: The Selfish Giant - it's grim but gripping up North

It's a long way from the Victorian England of Oscar Wilde to the Buttershaw Estate in Bradford, the setting of Clio Barnard's updated version of Wilde's fairy tale. The wonder of Barnard's very moving film is that, although shot in gritty realist fashion against a backcloth of extreme deprivation, it is true to the spirit of Wilde's story.

Barnard elicits magnificent performances from her two young leads, Conner Chapman and Shaun Thomas. They play Arbor and Swifty, 13-year-old kids excluded from school and forced to fend for themselves. Arbor is foul-mouthed, truculent and abrasive. To the authorities, he is simply a troublemaker who deserves to be pushed as far away from mainstream society as possible.

Barnard, though, shows an entirely different side to his personality. He is a teenage entrepreneur, resourceful, hard-working, loyal to his friend, devoted to his mum, and with a sense of defiance that often makes him seem like a pint-sized version of Albert Finney in Saturday Night and Sunday Morning. Like Finney's Arthur Seaton, he doesn't want to let the bastards grind him down. Thomas's Swifty is good- natured and trusting. He is also overweight and a victim of bullying.

Together, during their enforced absence from school, the boys enter the scrap-metal business, collecting bric à brac for local scrap merchant Kitten (Sean Gilder from TV's Shameless). He's a brutal and manipulative figure, a "bastard" as Arbor quickly realises, but also the only one to give the boys a chance (albeit for his own selfish reasons).

The world depicted in A Selfish Giant is very bleak. Unemployment is rife, one reason why there is such ferocious competition in the scrap business. Copper wire that can be stolen (at risk of electrocution) from power lines is the new gold that the scrap dealers are pursuing in their version of a Klondike rush.

The boys' mothers are struggling with the rent. Bailiffs, police officers or social services are continually turning up at their doors. They can't pay their utility bills and are reduced to selling their own furniture to survive. This is a world of smackheads and drunkards in which violence is taken for granted. Arbor encounters it in the playground and, most terrifyingly, in Kitten's yard. He is an adolescent kid and yet is forced to assume responsibilities that adults would balk at.

Even in such settings, Barnard is always looking for the humour and lyricism. The two boys are an odd couple – one small and scrawny, the other very big – who rekindle memories of the friends adrift in Depression-era America in Of Mice and Men. They always stick up for one another.

The scrap merchant's horse serves a similar purpose to the kestrel in Ken Loach's Kes (1969). That's to say, it gives the characters a perspective beyond that of their brutal everyday world and a connection to the natural world.

Kitten himself has a passion for trotting. In the film's most spectacular set piece, we see trotting horses racing at dawn down a public road with an army of cars and vans following behind it. Kitten's motivation is money – he has gambled heavily on the race – but the trotting race is the only occasion in the film in which we see him away from his scrap yard. When Arbor is shown grooming the horse or Swifty whispering to it, trying to calm it down, they too are able to forget about their predicament.

At times, cinematographer Mike Eley, who also worked on Ken Loach's The Navigators, shoots the film as if it's a kids' adventure story, not just a grim parable about excluded children. He has an eye for landscape and for poetic and jarring juxtapositions. We see the horse and cart turn up at the school or trundling down the Bradford roads, leaving a huge traffic jam in its wake. There are spectacular shots of crepuscular Yorkshire skies that make even huge pylons and factory chimneys seem poetic.

Barnard was partly inspired to make A Selfish Giant after reading Wilde's story to her own children. The other main spark was her experience shooting her previous feature The Arbor (2010), her documentary/performance piece about the Bradford playwright Andrea Dunbar, who wrote the screenplay for Alan Clarke's Rita, Sue and Bob Too! It's an unlikely but rewarding collision of influences. The film still just about has the quality of a fairy tale. Arbor and Swifty are the children with nowhere to play. Kitten the scrap merchant is the selfish giant who scares away the seasons. At the same time, there is a polemical dimension here – an obvious anger at the way the kids are abandoned and let down by a system that has no interest in them.

In its weaker moments, the film takes on the quality of a Victorian morality fable. There is an underlying sentimentality here that isn't entirely excised. Gilder's character has a touch of Oliver Twist's Bill Sikes about him and a Nancy-like wife who always looks tenderly at the kids, even as her husband rips them off or threatens them.

The Selfish Giant isn't exactly a film pitched at kids. One irony is that its 15 certificate will stop cinemagoers the same age as Arbor and Swifty from watching it. Meanwhile, adults may be put off by the fact that it is inspired by a children's fairy story.

It would be a grave misfortune if Barnard doesn't find the audience she deserves. Then again, regardless of its initial box-office performance, The Selfish Giant will have a very long shelf life and will be watched for years to come. Barnard's updating of Wilde is certainly one of the strongest films in what is shaping up as a vintage year for British cinema.