Somers Town (12A)

Because his new film, Somers Town, was financed by Eurostar, there's been some suspicion that Shane Meadows has made an extended commercial for the rail link. Certainly, from the British side of the equation, Somers Town is good advertising. A character enthuses that Eurostar will get you to Paris in two hours, and a coda reveals that the French capital, shot in colour, is a lovely place where you can ride merry-go-rounds and eat waffles to your heart's content.

But Meadows isn't so traditional when it comes to touting London. French viewers could easily think that, coming to a city shot strictly in black and white, they'd get to see only a few nondescript streets above Euston Road; would get their laundry stolen by homeless strays from the Midlands; or at best, if they're female and attractive, be given a whirlwind wheelchair ride round the old gasworks by adoring lads.

So no, Somers Town isn't a come-to-the-sunny-Smoke postcard, nor it is entirely a realistic picture of north London – yet it is a real picture of north London as seen by Shane Meadows, and since he's one of British cinema's authentic talents, that's plenty to be getting on with. This economic little piece is essentially an odd-couple comedy about two teenage boys at a loose end in the square mile behind St Pancras station, seen here still in last year's state of reconstruction. They team up, scuffle for a few bob, get drunk, then – after a feather-light wish-fulfilment ending – are left hanging, with uneasy futures to look forward to. Thomas Turgoose – so remarkable as the pug-faced young protagonist in Meadows's skinhead story, This Is England, – plays Tomo, a teenager from a Nottingham care home coming to London in search of a better life. Penniless and roughed up by locals, he teams up with Marek (Piotr Jagiello), the son of a Polish labourer on the St Pancras site. Diffident, moon-faced Marek spends his days taking photos and solemnly contemplating his portfolio of Maria (Elisa Lasowski), a French waitress at a local café.

At 72 minutes, Somers Town feels somewhat like an extended short, recalling the happenstance feel of the early French New Wave, capturing the feel of a particular moment in a city's history. But Somers Town is only incidentally about the changes around St Pancras: that's all happening in the background, while Tomo and Marek are simply supporting players, cooling their heels on the sidelines.

The film is scripted by Paul Fraser, but as with Meadows's best work, it has the feel of easy knockabout improv. Meadows loves the casual rhythms of people's presence and the odd sounds they make: he's fascinated by the Polish dialogue between Jagiello and Ireneusz Czop, who plays his simpatico dad; and by the way that the two leads' voices intertwine in their duets, Jagiello's airy mutter set against Turgoose's raucous, aggrieved whine. The other voice completing the trio is the cockney foghorn of the priceless Perry Benson, as a buffoonish small-time chancer who befriends the boys.

British film-makers dedicated to social realism might sniff at the buoyant fairy tale that Meadows offers here. There's undeniably a streak of downbeat realism in the background, in hints of Tomo's unhappy past, and in the Poles' lonely exile. But overall, there's no denying a note of cheerful unreality: notably, in the boys' relationship with the waitress who gamely agrees to play Jeanne Moreau to their Jules et Jim. Maria is barely a character, just transparently an affectionate vehicle for the boys' fantasies.

The film's most striking achievement is the way it makes improbably romantic capital out of very limited and mundane material: a handful of streets, photographed by Natasha Braier in crisp, radiant black and white. Somers Town is a minor Shane Meadows work – warm, relaxed, just the right side of ingratiating. But its casualness is part of the appeal: Somers Town doesn't feel the need to make a song and dance about its material, but just relishes the incidental. Meadows's film is unlikely to make you want to stop off in Somers Town en route to Montmartre, but if you do, you'll know not to leave your laundry unguarded while you're there.