James McAvoy continues to assert himself as one of the finer actors of his generation. In his new film, Filth – one of Irvine Welsh’s fruitier novels – fans of the Scottish actor might just have their nerve tested as he indulges in possibly the worst (and best) character created by the Trainspotting author.

James McAvoyMcAvoy in Welcome to The Punch.

Bruce Robertson, as you’ll see in the trailer below, is a narcotic-infused, alcohol-swilling, nymphomaniac party-beast who also happens to be a part of Edinburgh’s police force. He’s PC Bruce Robinson, but he isn’t politically correct, not one bit.

Filth is "bonkers,” asserts McAvoy, according to The Guardian.

“It asks a lot of the audience, and there will be people who walk out of the cinema, I'm sure of it. And there will be people who don't understand it and get totally lost. But for those who get it, I think they'll really love it," he adds. "Our editor saw it and he said James is unbelievable in it – but whether anybody will ever get to see it 'cause it's so out there…"

Rookie director John S Baird adapted the script, and he couldn’t have chosen a more challenging project. With funding hard to come by due to the lewd nature of the film, he had to look abroad – reaching as far as Sweden and Belgium - for money – culminating in a total of 26 producers being credited.

Check out the trailer for Filth (18+)

"Some people didn't like it," explained the Last King of Scotland actor. "But for people who do like that, I wanted to be able to give a million per cent, and leave nothing behind. Leave a lot on stage; leave a bit of yourself on stage. I like other kind of work, too," he adds, "contemplative pieces, or cerebral pieces. But my favourite kind of theatre is seeing people sweat blood."