Shane Meadows, director of TwentyFourSeven and A Room for Romeo Brass, has made what is arguably his most successful feature so far. It has laughs, nice performances and some genuine emotion. It is easily the equal of overpraised British milestones such as Billy Elliot and The Full Monty, and miles ahead of all those lottery-funded quasi-comedies. Meadows's alchemy works: that tricky mix of unassuming British littleness, pluck, daring and self-deprecation.

Initially the movie plays on the comic discrepancy between tatty real life in Britain and Hollywood myth: it alludes to Sergio Leone, and there is a genial pastiche of Morricone on the soundtrack. But Meadows ensures that his tale of dysfunctional trailer-trash folk at war, starring Robert Carlyle, Kathy Burke, Rhys Ifans and Shirley Henderson, is not simply a big joke.

Meadows gets cracking performances from his leading players. Henderson is outstanding as gentle, sensual single mother Shirley. Her innocent determination to have what she wants inspires protective love in her partner Dek (played by Ifans, whom Meadows gets back on comic form). Burke gives an easy-going comic turn, but with scary flashes of anger. Carlyle's hard-man persona has in the past often looked hard-wired; Meadows modifies it by getting him to play to his tough-guy strengths while making him believably smitten with his deserted family.

It is a treat, and a relief, to see that a British film can combine sentiment with drama and laughs without looking phoney. Once Upon a Time in the Midlands is that most difficult of movies: a lovable comedy with broad yet subtle comic performances, authentic and suffused with warm-heartedness. It is the sort of thing that only looks easy when you are getting it right. And Meadows is getting it right.

· At UCG tomorrow and Glasgow Film Theatre on Thursday. Box office: 0131-623 8030.