Not many actors are as interested in their more famous fellows as is Michael Sheen. On television he has played Tony Blair and Kenneth Williams; on film, Oscar Wilde's lover, Robbie Ross, and (coming soon) Dylan Thomas; and on stage, Mozart in Amadeus, and Caligula, for which latter performance at the Donmar Warehouse he won both the Critics' Circle and Evening Standard best actor awards in 2003. Now the 37-year-old Welsh wizard from Port Talbot, home town of Richard Burton and Anthony Hopkins, returns to the Donmar playing someone - perhaps the only person - who could happily interview the whole crowd of them: David Frost.
Yes, Sheen will indeed be saying "Hello, good evening and welcome" at the start of Peter Morgan's Frost/Nixon but we know from past experience that there will be a lot more to his portrayal than surface mannerisms.
Sheen had not met Frost until a television awards ceremony last year when, at every mention of Frost's name, the television cameras swung round on the actor. Not until Frost was called to the stage to receive a lifetime achievement award did Sheen realise that he was sitting in front of him.
Sipping on an iced fruit juice in a fashionable Soho club on a glorious summer afternoon, Sheen, wearing a grungy black T-shirt and three-quarter-length jeans, elaborates: "I knew I was doing this play, so it was really spooky. I look forward to getting to know him a bit better. I can't remember a time when I didn't know who David Frost was. But it's hard to match up the mellow Sunday morning television interviewer with the harder, cooler 1960s model - when he was often referred to as the fifth Beatle - and, again, the playboy jet-set creature of the 1970s."
Frost, in short, became as famous as the people he interviewed, and his epic encounter with Richard Nixon after the Watergate scandal is one of the cleverest entrapments of all time. Nixon thought that the new-style establishment "sycophantic" Frost would be no trouble. And, indeed, the first four sessions were amiable enough. Then, the wily media star held Nixon's hand while he confessed to his crimes and admitted the cover-up.
This is the climax of the play. Sheen explains that Frost risked everything to get his story: "None of the big studios was interested, so he put up all his own money. He stood to lose a fortune but he made one instead. Because immediately Nixon made the confession, everyone wanted the programme. The play looks into all that, it's not just the interview."
I am able to fill in Sheen on a few Frostie details - his off-screen gruffness, his heavy cigar-smoking, his curiously unmanicured fingernails - but I lay him low with the big one: Frost, like Sheen, was nearly a professional footballer. As a 17- year-old, the man of whom it was once said that "he rose without trace" was offered a contract by Nottingham Forest.
The 12-year-old Sheen was talent-spotted by an Arsenal scout, the father of Tony Adams, the former Gunners captain, while playing against Adams - "I skinned him a few times" - in a series of challenge matches on the Isle of Wight.
Adams Senior wanted to take little Michael straight off to Highbury to join the youth team. But the family demurred, and by the time he was 16, Sheen had lost interest in playing professionally, though he did play for South Wales schoolboys and had trials with the league teams at Swansea and Cardiff.
He says: "Although my family - parents and sister - all work in the personnel management business, their real passion is performing, amateur operatic societies and so on." Here's another triviality stunner: Sheen's father is a part-time Jack Nicholson lookalike, making television commercials abroad and "guesting" at huge parties and awards ceremonies.
Sheen's girlfriend, Lorraine Stewart, is appearing nightly at the London Palladium as a dancer in Sinatra; the couple met when Sheen went backstage to see his actor cousin, Caroline Sheen, after a performance of A Funny Thing Happened on the Way to the Forum at the National in which Stewart also appeared in a small role. Sheen has an apartment in Santa Monica, California, and two of his current personality obsessions, the critic Kenneth Tynan and the politician Bobby Kennedy, both figure in Santa Monica folklore. Tynan went there when he was dying, to try to cure his emphysema in the benign climate. Kennedy was assassinated in the Ambassador Hotel.
Sheen wants to make a film based on Tynan's brilliant New Yorker account of Nicol Williamson's visit to the White House to perform for President Nixon; and of Kennedy he says: "I think he's an extraordinary figure. Nobody's done a film or theatre piece about him. He was much more interesting than his brother JFK."
Sheen left Rada in 1991 before completing his course, in order to appear as a young Greek pianist in Martin Sherman's play about Isadora Duncan, When She Danced, starring Vanessa Redgrave. His impact was immediate. When he played Romeo at the Royal Exchange, Manchester, in the following year, I rashly - but not unjustifiably - said he was the best young actor of his generation, invoking comparisons with such wolverine peers as Nicol Williamson and Jonathan Pryce. Television stardom soon followed in a Ruth Rendell series, Gallowglass.
Unusually, he transmits a sense of danger on both stage and film. Always described as elfin or impish, he is indisputably electrifying as well as being technically fearless. Paul Taylor, reviewing his 1994 Peer Gynt at the Barbican (directed by the Japanese maestro Yukio Ninagawa), itemised his potential for greatness: his powerful voice, instinctive presence, ability to flip between comedy and tragedy at once, his androgynous sexuality. Over the past decade, he has continuously worked with the best: Cheek by Jowl (a wonderful Alfred de Musset and Ghelderode double bill); the Almeida (playing one of Pinter's "sponging, parasitical pair of ponces" with Douglas Hodge in Moonlight); the RSC, where he was an ecstatic Henry V in 1997; and the National, where he reprised his definitive 1995 Royal Exchange Jimmy Porter in Look Back in Anger four years later.
He returned to the National last year as a dodgy estate agent in David Farr's update of Gogol's masterpiece, The UN Inspector, maniacally visiting a corrupt ex-Soviet republic with wonderful delusions of celebrity that must have been mother's milk to him: his over-the-top ham Martin Gammon character had not only written both Dickens's Our Mutual Friend and Ian McEwan's Enduring Love, he had also sauntered round the White House rose garden with George Bush and appeared on Celebrity Big Brother with Harold Pinter.
He has illuminated several films, notably the underrated, under-distributed Heartlands (2003) in which he played an eccentric, cuckolded darts player trying to win back his wife in Blackpool.
But no sign of Hamlet yet? "I've played so many alternative Hamlets I'm beginning to lose interest. What I'd really like to do is play alternating performances of Hamlet and Richard III in one season, because, as an actor, you're not supposed to be able to play both." If anyone can, he can. Kevin Spacey could do worse than programme the idea at the Old Vic next year.
Meanwhile, Sheen remains best known for playing Tony Blair and Kenneth Williams. In The Deal (2003), he was a cunning Blair to the fleshy Gordon Brown of David Morrissey, as they settled their partnership over a legendary meal in Islington.
The same director, Stephen Frears, has now signed Sheen as Blair again (the which Blair project?) in the upcoming cinema release The Queen, in which Sheen's Tony advises the royal family (Her Majesty is played by Helen Mirren) on how best to deal with the aftermath of Princess Diana's death, just a few months into his premiership.
As the outrageous, and outrageously sad, comedian Kenneth Williams in Fantabulosa! earlier this year, he miraculously combined camp floridity with inner truth, often in the subtlest, tiniest gesture, such as the backward flick of his head.
"It's weird," he says, "that I've ended up playing so many real live people, because I was never any good at impersonations at school. You have the end result ahead of you. As an audience, I always feel, you'd be disappointed if you didn't get that. And you'd be equally disappointed if you didn't get more than that."
'Frost/Nixon' opens at the Donmar on 10 August (08700 606 624)Reuse content