'I'm still not cool enough for the Citizens'

What? "I once fancied appearing in Friends," says the Glasgow-born actor, while pouring tea in his dressing room in London's Duke of York's theatre. "And I'd still like to appear in a Woody Allen movie. But that's as much ambition as I've ever had."

Sinclair not only has no need whatsoever to show the world his Coriolanus, he reveals he's only appearing in current hit Jeeves & Wooster: Perfect Nonsense because he really likes director Sean Foley's very clever staging. And to further confound expectation, the actor reveals he doesn't actually like actors much. "I can't stand all the luvvy, neediness of it all. And I really don't like it when people refer to me as an actor."

But you are one. You have been since your Glasgow Youth Theatre days. And as soon as Gregory's Girl appeared in 1981, the title was stamped indelibly into your being. "I know," he says, smiling; "I wonder sometimes if that's something I should get help with."

Fame, Sinclair may argue, seems to have arrived at his Knightswood doorstep like an unexpected, excited aunt from America, taking him by the hand to London, and television and West End theatre.

"I don't think about things too much," he claims. Yet, as we chat, it's clear Gordy (as friends call him) is talking nonsense. There aren't many former apprentice electricians from Knightswood who light up when talking about French existentialists such as Albert Camus and cynical American philosopher Noam Chomsky. Is the reluctance to acknowledge your acting career about not having gone to drama school, or stinted in rep theatre?

"I don't know," he ponders, then adds, referencing the world of therapy again: "I think I'd like to talk to someone about why I feel insulted when people call me an actor."

Yet, as a teenager he reveals he tried to get a job at Glasgow's prestigious Citizens' Theatre. "But I wasn't cool enough for the Citz. Come to think of it, I'm probably still not cool enough." Sinclair won his Olivier Theatre award in 1995 for She Loves Me, (he's also had rave reviews for The Producers and The Ladykillers) yet, curiously, the National Theatre of Scotland doesn't have his number on speed dial. "I never get asked to work in Scotland," he says with a shrug.

Does he actually enjoy acting now? " I'm comfortable on stage these days. I don't tend to get nervous any more. I get a bit darker when I'm trying to learn my lines, but not on stage."

He's excellent in Jeeves and Wooster (set to tour Scotland), playing five characters, including the butler who is dryer than a pink gin. The plot is perfect nonsense, the narrative almost non-existent but it's great fun; think Kind Hearts and Coronets meets 39 Steps.

The show is dependent upon 19 quick costume changes. How does he cope when things go wrong? "I quite like it," he says mischievously. Why? Is this because you're slightly mentally disturbed? "I don't know," he says, smiling. "You'd need to ask someone more professionally qualified than me. But I like it so long as the audience are with you. I hate to see actors laughing amongst themselves on stage. That's just twatting about."

Does he feel the job to be frivolous? "I don't know. But when I hear actors talk about serious subjects I tend not to take them seriously, and I don't know why that is."

What about when he landed his Olivier? That must have been a moment to savour? "Not really," he says, deadpan. "What I remember about the award was Jane Horrocks, my pal, presenting it to me. But Jane's boyfriend at the time was Sam Mendes and our show was up against his show. We won five Oliviers that night and she didn't hand me the award, she threw it at me and said 'Here!'"

Why does Horrocks make the cut as friend? "She's not a luvvy darling. She's her own person." He adds, with a wicked grin: "I was in this very theatre with Jane in Sweet Panic (2003) and I realised she has mild OCD; move a cup and she switches it back. So when she turned around I'd move the cups around, just to play with her head."

Do other actors get miffed about his criticism of the job? "Yes. A friend of mine read an interview I did and told me to turn it down a bit. He says it's all a bit too honest."

Sinclair's honesty extends to his own limitations. "I used to go to the showbiz parties, because I figured that's what you do. But I felt incredibly uncomfortable. I'm just not good at small talk. I just didn't want to be there, to the point I felt I should go talk to someone about that, to find out what's wrong."

Again the hint at analysis. But Sinclair did run with the acting crowd for a while. Did he enjoy the attention of the ladies? "I wish I'd been a bit more aware of how it all worked," he says, grinning at the sexual opportunity that befalls the famous. "When girls were interested I didn't know about it until later. I was a bit of a tube."

He once dated Peter Brooks's daughter Irina (his co-star in The Girl In The Picture, 1985) who held up a mirror when she shoved a book into his hands and suggested he read it. It was The Outsider by Albert Camus. "I read it and realised it was about a sociophobe, someone slightly disturbed and removed from society. I identified with the character, but I didn't realise at the time why she'd given me the book."

You are who your friends think you are? "Yes, maybe I do need help," he says.

Not too much. If Holden Caufield were re-born in Glasgow in 1962 he'd have been christened John Gordon Sinclair, but it's refreshing to meet an actor who is immune to hyperbole.

When he tells his Hollywood story, when he was once sent to see a casting agent, you realise he's still grounded. "I went to an 11.30 meeting and it got to 12 o'clock and this woman was still on the phone so I got up and left. My agent went mental. But I didn't bother. I just had a holiday and enjoyed myself."

Sinclair is now happily married to doctor wife Shauna (they were introduced by Clare Grogan, who was his Gregory's Girl all those years ago), they have two little girls and live in Surrey. And he reveals that's where his next professional appearance will take place. In his shed. In the past two years he has become a successful writer, with two dark thriller novels, Seven Times Seventy and Blood Whispers, published to great critical acclaim. Can he call himself a writer? "At the Edinburgh Book Festival I got a little badge with 'author' on it. And I got a little buzz out of that."

Does the garden shed life suit his personality? "Yes," he says, with delight in his voice. "I absolutely love it. I love painting pictures using words, figuring out how to create suspense. I remember writing a line and then laughing out loud. I thought; 'How the hell does that work?' It's like telling yourself a joke."

At the end of the year, Sinclair plans to pull down the curtain on acting for the foreseeable to write (so see him in Scotland while you have the chance). He may never return to acting, if book success continues. But has he ever considered therapy, given his strange relationship with thespianism? "No, because I'm Scottish," he says, deadpan. "So you work out things in your head. For example, if you feel that uncomfortable about parties you just don't go. Plus, if I told my mum and dad I was seeing a therapist they'd tell me to catch myself."

So he's happier these days, set to face the world as a writer? "Kind of," he says. "I'm not complaining. In the grand scheme of things, I've been lucky. But I tend not to think about things too much."

Perfect nonsense, you say, and he laughs in agreement.