As a vengeful Liverpool fan, a wayward Highland cop, and a hard-drinking Edinburgh hardman, he proves himself ready to join the ranks of the actors he most admires - De Niro, Keitel and Oldman. He has their scene- stealing danger and electricity, he has the ability to submerge himself wholly in the murky, toxic depths of his characters. And he has their penchant for playing psychopaths. "Those are the parts, aren't they? There's just much more in those characters to get my teeth into."
He also has a face that slices its way into your memory. Cheek-bones like daggers, an arrow-point nose, wide, wide, probing brown eyes, lines scored deeply above them. And yet it wasn't until the closing credits of Trainspotting that I realised who was behind the Tennent's-fuelled time bomb, Franco Begbie. For someone whose face is so distinctive, Carlyle has a knack of metamorphosing from part to part. When I meet him at the launch of Hamish Macbeth's second series, in London, his haircut is somewhere between Begbie's and Hamish's, centre-parted and reaching the collar of his black denim shirt. His face seems to have fewer sharp edges, and the overall softening effect makes him, again, difficult to recognise. But Carlyle, 34, can be almost as intense in conversation as he is on screen. Now and again, the lips become thinner, the lines tighten around the nostrils and the masks of Hamish or Begbie appear.
He rejects the term "Method acting", and says that it is "honesty" that requires him to transform himself into the people he plays. Apparently, he kept his Scouse accent throughout the filming of Cracker, even when another actor rang him at 3am. Is that true? "Absolutely. You could call that Method if you wanted, but for me it's just about the honesty and the believability. It wasn't believable to me to be speaking like this, in a Glasgow accent, and suddenly to turn on Albie's accent when I walked on the set. That becomes acting." He spits the word out of the corner of his mouth in distaste, crushing it with italics. "You know what I mean? Acting. It should be about being."
This is a little worrying, considering Carlyle's nice line in nutters. If you've been cracking snooker cues over people's heads as the sociopathic Begbie all day, isn't it dangerous to have his traits festering in your head when you socialise in the evening? "I know what you're saying, but no," he says. "I don't go out when I'm working at all. It's my responsibility towards the producers of a piece to give them everything that I have. If that means staying in for a couple of months, then it's a very small price to pay."
This commitment, which partly explains the power of his performances, must make it hard to maintain a relationship during filming. "It's impossible. It's absolutely impossible. I don't really have much time for anything else, socially or otherwise. But I really enjoy what I do. It is my life. And I'm the luckiest bastard on the planet that I'm able to do it."
Recent articles have said that Carlyle has a girlfriend, but the BBC's publicist has warned me that he will walk out before discussing his private life. I get as far as inquiring if he has any brothers or sisters. "Not talking about it," he says before the question is finished, his hand karate- chopping the air. "I'm not talking about it, honestly. I'm no' being precious about it, I just think it's boring. Last year I told the press a wee bit about my background, and they took advantage of it. This year it's different. I keep my personal life very, very private, and that's the way I like it. Anybody intrudes on it then Franco Begbie'll be payin' them a visit."
He's joking - I think. Earlier he told me that he is nothing like Begbie - "I'd run a mile from a fight" - but there's something about the desert dryness of a Robert Carlyle joke that makes me change the subject all the same. His reticence is more than justified. The Sunday Mirror interviewed his mother last year, even though he had had no contact with her since she left the family when he was a child.
Carlyle grew up with his father on a number of hippie communes, mainly in Maryhill, Glasgow, near to where he lives now. He was a painter and decorator between the ages of 16 and 20, until amateur dramatics led to a place at the Royal Scottish Academy of Music and Drama. Is that where he learnt his obsessive approach to characterisation? "Certainly not. Drama school was not a particularly pleasant experience for me. What I had in amateur theatre was rawness and energy, and that's the thing that drama schools try to squash out of you. They don't like ragged edges. They try to put you on this conveyor belt, give you standard English, so that you come out as The Complete Actor." His sarcastic tone is scalpel- sharp. "After I left drama school it took me four years to rid myself of the stuff that had been poured into my head in that institution."
He co-founded Rain Dog theatre company, as a "scream against Scottish theatre as it was at that point". Tired of the very structure of scripted drama they improvised their own plays - and still do. When he has time, he directs for Rain Dog, but he still has a bias against actors who have been to drama school, and prefers film and TV to what he considers the artificiality of theatre. "If you look at a performance in a particular film and there's something in it you don't believe, nine times out of 10 that's because the actor's posturing rather than being, and that comes directly from theatre."
It's a view that was bound to appeal to the film-maker Ken Loach. Carlyle was one of 120 actors who auditioned for the lead role in Loach's Riff Raff. He won the part, that of an ex-con, Stevie. (He has just finished a new film with Loach, Carla's Song, in which he stars as a bus driver caught in the turmoil of Nicaragua.) After Riff Raff he promised himself he wouldn't return to inferior work, and turned down substandard jobs for two nerve-racking years until he was offered Safe, directed by Antonia Bird (who would later cast him as the lover in Priest).
Hamish Macbeth doesn't quite fit into the pattern of extreme, gritty roles: "When the idea was first mentioned to me, I thought, 'This sounds like a nightmare.' Then I got the scripts in from Danny Boyle [the writer, not the Trainspotting director] and I saw something else in the character. He'd joined the police during the Thatcher years, and to come out of that and have no ambition whatsoever seemed to be quite interesting. With the other character traits, like the hash smoking and his inability to converse with women, it seemed that this wasn't your conventional Sunday-night telly."
Indeed not. Hamish's beat is magically offbeat: the humour is tinged with sadness, the shortbread-tin lochs and hills are enshrouded in surrealism. The series has little in common with the whodunnit novels that inspired it. "Their only resemblance to the programme is my photograph on the cover," sneers Carlyle. "M C Beaton is a very lucky woman. She complained bitterly that they'd turned her lovable hero into this dope-smoking layabout. She should take the money and run."
Initially, he wasn't sure he was right for Train-spotting, either, despite being a fan of the novel. "Begbie didn't seem to be the obvious part for me, even though I've played a lot of these kinda parts. I'd seen him as being six-foot-five in all directions. But, as Danny said, 'small psychos are the best'."
! The second series of 'Hamish Macbeth' starts on Sunday 24 March on BBC1.