In Dirty Pretty Things, Frears challenges the UK tabloids' party line about immigrants coming over here and stealing our women and sleeping with our jobs, or some such rubbish. The salient truth is, if you don't have a passport and you try to get a job in this country, you will be deported. Okwe and Senay live under the radar, having to medicate cabbies' venereal diseases and fellate sweatshop owners to scrape a living together. Moreover, the locations are dirty and urban- this is not a Visit London advert or a latter-day Woody Allen film. Life in the capital is not so great for a certain part of the population, and that Frears manages to convey that without being preachy is quite a marvellous achievement, due in no small way to the excellent cast he has assembled.

For starters, it has to be noted that Chiwetel Ejiofor is an incredibly underrated actor. Though this film was his breakout role, it doesn't feel like he's making the impression in the film business that he should be. Despite working with Alfonso Cuaron, Spike Lee and Joss Whedon since this film was released, we have to wait for someone to sit up and take notice instead of watching him as a bit player in the likes of Roland Emmerich's 2012. But while we wait, there's always his lead performance here as Okwe, which is just tremendous, sympathetic and understated. Audrey Tatou lends him ample support as Senay, bringing to the role that naivety and innocence she always does so well. There's also a lot to be said for Sophie Okenedo and Benedict Wong, both of whom take briefer parts as potentially stereotypical figures (tart with a heart anyone?), but still make them three-dimensional. Such emphasis on casting is necessary because there are times when I felt the script for Dirty Pretty Things verged slightly into melodrama, but the superb peformances elevate the film beyond that.

While there's nothing wrong with a bit of melodrama here and there, it wouldn't quite sit right in a film with so much social commentary. That said, Frears is occasionally guilty of quite cliched touches to remind us whose side we're on- the immigration police who pursues Senay are the authorities, but to counter the audience's expectations, the principal cop has five o'clock shadow and a tremendous black moustache. He could scarcely be more signposted as a baddy if he were wearing a top hat and tying Senay to a train track. It's difficult not to find things overdramatic when you have someone like that on your tail. On the other hand, the film's message outweighs the more dramatic aspects, a refreshing change from the Oscar fodder that outperformed the film at the box office at the time of its release. Crucially though, while few people can even remember which film beat Dirty Pretty Things to awards success at the Oscars and the BAFTAs back in early 2003, this is a film that's as relevant and memorable now as when it was released.

Swerving any kind of three-act narrative structure proves a boon for this film, as Dirty Pretty Things instead stands as a microcosmic look into the lives of two characters- the opening of the film is not the beginning of their story, nor do the closing credits signal their end. Its message is wrapped up in the lives of the endearing characters, and it has a humanity seldom seen in "social movies".