According to Michael Sheen there's only one man fit to play Old Big 'ead, Brian Clough. Like Clough, Sheen was a talented footballer cut down in his pomp. But while Clough scored 251 goals in 274 professional games before injury did for him, Sheen's career came to an end a little earlier. He was 12 years old, and had just been offered the chance to sign for Arsenal as a youth player. Not that he was supposed to know. He just happened to overhear his parents discussing how the family would have to move to London and that was an impossibility. Sheen stormed upstairs, kicked everything in sight and never said a word about it to his parents.
He returned to Baglan boys' club, his local team in Port Talbot, continued to play with Hoddle-esque grace, and won player of the year, but the dream had died.
Even now, he says, there is nothing, absolutely nothing, in an actor's life that can equal the feeling of scoring goals and lifting trophies.
When it came to shooting The Damned United, the adaptation of David Peace's haunting novel about Clough's disastrous 44-day reign at Leeds United in 1974, the cast was chosen as much by football skill as acting ability. "There was a lot of competition among the actors and I used to say, 'Well, hands down it's me, you might as well give up, I am the best footballer.'" Did he really think that? "I did. Partly influenced by my being Clough at the time."
I ask him if he is big-headed innately. He thinks about it - for a nanosecond. "Well, yes I am. I joke about it, but I am really big-headed." About everything? "I like to think that I joyously celebrate my gifts." Which are? "My chief gifts are - naturally good at all sports with a raw talent for pretty much everything, which if nurtured could develop into improper talent. I always say if I'm not good at something it's just because I've not had time to focus on it ... it's just uncrafted, like a slab of rock that contains the statue of David within it." He comes to a stop, and smiles contentedly.
There are so many surprising things about Sheen. I expect him to be impish and fey. In fact, he's verging on the rugged. Then there's the accent. Yes I know he's Welsh, but I still expect him to speak in an English accent - after all, he's spent the last few years portraying resolutely English characters such as David Frost, Tony Blair (despite the Scottish roots), Kenneth Williams and now Clough. But his voice is deep, lilting, sing-song Welsh.
Sheen is 40 now, but it's only since he first played Blair in The Deal in 2003 that he has become a major screen presence. For many years he worked quietly, successfully in theatre, which he assumed was his natural environment. He has now collaborated on five films with the writer Peter Morgan - three times as Blair (the final instalment, about Blair's relationship with Clinton, is on its way), once as Frost, and now as Clough. Sheen's Clough is more likable than the obsessively brooding alcoholic of the Peace novel. He swaggers just like the legendary football manager, and delivers his lines perfectly with that smart-arse, corrective whine, even if he can't fully capture his terrifying charisma.
It's an unusual role for Morgan to write for Sheen. Morgan tends to dramatise conflicts between two huge egos - one monstrous and relatively transparent, the other more unknowable. As Frost and Blair, Sheen has played the quieter, more mercurial character. And with good reason, Morgan says. "Here's the funny thing: I've spent five years with him and I don't know Michael at all. We have a very courteous and respectful relationship. This is why he plays Frost and Blair so brilliantly, because he's inscrutable - and there's a brilliance and inscrutability to all of them."
Morgan says Sheen is the most technically accomplished actor he has seen. "He can be doing a long speech and when he's finished, I'll say to him, 'You know that line three-quarters of the way through the speech? I'd like to replace it,' and he'll say, 'OK no problem' and just do it. He doesn't flicker. It's like a guy juggling 15 knives being told to juggle two more that are aflame. 'Oh, no problem.'"
Of course I'm inscrutable, Sheen says, I'm an actor. "My career is pretending to be other people so inevitably there is a covered-up-ness about that in itself. I can't remember who said it, maybe Oscar Wilde - give a man a mask and he reveals his true face. I guess I'm more comfortable revealing myself through saying, 'This isn't me, this is Brian Clough, but actually it is me.' I put the characteristics of somebody else on, but what I'm revealing is actually about myself."
Sheen says that when he plays real people, the voice and mannerisms are only the start. But he is increasingly being referred to as an impressionist. Does that worry him? "It doesn't worry me but it's wrong. I hope people will be able to think about it a bit more and see it's not an impression. I don't do impressions. With absolutely no disrespect, give the script of The Queen or Frost/Nixon or Damned United to Rory Bremner or Alastair McGowan and let's see ... but likewise I could try to do what they do and I would look a twat because I can't do it."
While many actors insist there is nothing autobiographical about the characters they play, Sheen goes the other way. He picks apart the famous people he has played, and reveals how in the end they are all him. "It's not just something of me. That's all I play - me. The secret to acting is don't act. Be you, with add-ons. Playing Clough I'm playing my own arrogance, that's all I can do. I can't pretend to be big-headed, I just have to find my own big-headedness, conceit, arrogance, whatever it is compensating for his insecurities. He was covering something up. The key for me was the injury when he was younger, when he was stopped doing something he was brilliant at."
Sheen finds Blair most slippery of all, reflected through a perma-smile more enigmatic than Mona Lisa's. Producer Christine Langan, who has worked with Sheen on five BBC films, calls it "the smile as carapace". Although his characters might ultimately be unknowable, she says Sheen's strength is ready access to his emotions. She cites a lesser known film - Dirty Filthy Love, in which he plays a person with Tourette's with visceral intensity. "It's extraordinarily emotional," Langan says. "He seems to cut a layer of skin away." The emotion, she says, is equally evident in Sheen the man. "He doesn't button up his feelings when he's angry about something. But it's often justified."
True enough, Sheen says, he can be a right pain when he's immersed in a role, and he doesn't argue as Michael Sheen, he argues in character. "There's a point where the boundaries have to be blurred." He insists it's a necessary point to get to, but admits it's confusing. "That's why I refuse to go on political programmes. I get invited on a lot because of my connection to Blair, and I always say no."
What are his politics? "I can swing between being as leftwing as Chomsky and as centrist as pfffft ... God, I don't know." Blair? Oh no, he says, appalled. "I'm left of Blair. But sometimes I can talk about how, 'Yes we should all go and live up trees and kill our own animals and barter', but then obviously I would feel like that because being naturally good at all things, I would then rule the universe. So basically I'm a Nazi I suppose." He stops, confused. "It's a mass of contradictions."
Sheen was born in Newport. When he was five the family moved to Liverpool before returning to Wales, to his parents' home of Port Talbot, three years later. "I grew up always feeling Port Talbot was my home and spiritual home, yet I didn't get there till I was eight, so I felt like an outsider. It's a place where I grew up finding out about theatre and acting and literature, yet the overwhelming atmosphere of the place was latent violence, so that's a weird mixture as well. I wanted to claim Port Talbot as my own, I wanted to feel I fitted in as much as everybody else did and yet I never really felt I did." He laughs. "So everyone else was desperate to get out of Port Talbot, and I wanted to get in."
He's always had issues with identity. Now he's an anglophile Welshman reluctantly living much of the time in Los Angeles - not for work, but for family. Seven years ago he separated from his partner and the mother of his child, Kate Beckinsale. He never tried to disguise the pain it caused him. Sheen and Beckinsale had been working on the film Underworld, directed by Len Wiseman. Afterwards, she left him for Wiseman - and they live in LA with Sheen and Beckinsdale's daughter Lily. I mention a Guardian Weekend questionnaire he completed in which every second answer seemed to mention how much he hates LA. He bursts out laughing. "I've had a complicated relationship with LA, but I'm coming to like it more. I think part of me has just gone, 'Look: shut up moaning about it, this is where you are.' The only person who suffers by me going on about how much I hate it is me."
Did he resent LA because of the split with Beckinsale? " It's a mixture of things. The reason I was in LA was because of my daughter. I hadn't chosen to go and live in LA, so that was part of my difficulty with being there. And how it affected everything else - it affected my partner because if she's going to live with me she has to live there as well." He has been with dancer Lorraine Stewart for five years, and says he's ready for fatherhood part two.
Is it true that he punched Jeremy Northam on the set of The Golden Bowl when the actor insulted Beckinsale? He nods, half cocky, half sheepish. "Sadly it is true." Did he hit him hard? "Sadly I did, yeah. It was because I thought he was being disrespectful to someone I loved." Was that punch a one-off ? "I think he may be the only actor I've ever hit." Who did he hit last? "I think it may have been a photographer in Los Angeles. A while ago. It's not a regular thing, it's just when people I really care about are under threat. That's one of the good things about growing up with the threat of latent violence around you, I guess." Port Talbot has previous with combative actors - it was also home to Richard Burton and Anthony Hopkins.
Sheen really is very Welsh, despite his fascination with the English. He loves to talk. About anything. So he segues from the greatest ELO songs ("Mr Blue Sky is an epic of grandeur and greatness") to the people he'd like to play (he'd love to give Ronnie O'Sullivan a go), to his favourite word: discombobulated. Why does he love it so much? "Every time I use that word, my girlfriend goes, 'Oooh I like that word,' and my daughter likes it as well. You could imagine a character on some kids show called Mrs Discombobulation - and in a truly Welsh sense it's trying to get as many syllables into a word as you possibly can." Anything else? "Yeah, it's a good way of describing what life is like most of the time."
