Heads Up: Irvine Welsh's Filth comes to the big screen starring James McAvoy

McAvoy's cop off the rails is tougher than 'Trainspotting'

James McAvoy as a drug-addled, booze-sodden, totally depraved policeman (Neil Davidson)

What are we talking about? An adaptation of Irvine Welsh's 1998 novel of the same name, which follows a bent copper named Bruce, investigating a murder in Edinburgh.

Elevator pitch Happy as a pig in muck: James McAvoy relishes his role as drug-addled, booze-sodden, totally depraved policeman.

Prime movers Jon S Baird has adapted Welsh's novel, and also directs; his previous film Cass, a British crime drama, had a lukewarm reception in 2008.

The stars McAvoy continues a spate of nasty guys (Trance; Welcome to the Punch; er, Macbeth) as Bruce, a role he was apparently desperate to get; plus strong British support from Jamie Bell, Imogen Poots, Jim Broadbent, Eddie Marsan, Shirley Henderson and Joanne Froggatt.

The early buzz Empire wrote: "The film adaptation of Irvine Welsh's provocative novel will [be] filthy… and boy is it fun. Where else are you going to see Eddie Marsan rubbing his nipples, or the young Professor X photocopying his nether regions?" Website Total Film is excited: "From The Last King of Scotland to Trance, it's clear that James McAvoy enjoys dabbling in the more morally dubious of cinematic tales. But we have a feeling Filth is set to top the lot. The first trailer … is about as shocking, rude and red-band as teasers get, showing that Jon S Baird has certainly nailed the tone of its inspiration." Website Cinema Blend added: "You watch a movie like Trainspotting and you think … 'it's probably as close to adapting Welsh's insane storytelling style as any film will ever get.' And then Filth reared its coke-nosed, booze-breathed, chokefucked head, shattering all former beliefs."

Insider knowledge They struggled to raise the budget of £3m – until Trudie Styler (wife of Sting) stepped in and stumped up. Cheers, Trudie!

It's great that … great minds see alike: Welsh had reportedly always wanted to see Bruce on the big screen – and a meeting with Baird convinced him he had the same vision ….

It's a shame that … it will naturally be compared to Danny Boyle's Trainspotting – a hard act to follow – and to the still in-the-pipeline follow-up, Porno.

Hit potential Looks properly grim, to judge by the explicit and, well, filthy, trailer – and that's just what Welsh fans will be after. May not play well with the grey pound or Americans, and definitely not one for a first date.

The details Filth is released in Scotland on 27 September and the rest of the UK and Ireland on 4 October