Stephen Merchant - would you fall for this man?

Stephen Merchant is one half of the UK's most successful comedy duo - and not just in terms of TV series franchised, movies produced and appeared in, Baftas and Golden Globes won. He and Ricky Gervais are among the richest comedians in the world: US website CelebrityNetWorth has Gervais worth roughly £50 million and Merchant a cool £22 million. And yet he still can't get a girlfriend.

One New Year's Eve, for instance, he was standing in Trafalgar Square when a good-looking girl reached up to tap him on the shoulder (he's 6ft 7in) and asked, 'Are you going to be here for a while?' In a second his whole night changed. 'Here we go,' he thought. 'This is it.' He was no longer crushed in the cold; he was a handsome winner about to get some New Year's action. 'Because me and my friends are all going off,' the girl continued, 'and we want to arrange to meet back here, at you.'

He sighs as he relates the story. 'That, to me, crystallises it,' he explains. 'Is it more possible to have sex with someone if you're famous? It's absolutely not like walking out of your house and women are running down the street like you're Bros.' He laughs for a second at the image. 'People think all fame is the same but being on BBC Two from time to time does not make you Warren Beatty. I honestly can't impress that upon people enough.'

Surely once he'd picked up a Golden Globe, live on television, women found him more attractive? 'No,' he says firmly. 'But I have become more confident in my own skin. That's the difference.' In part his awkwardness was due to his height - 'People don't mind insulting the tall. We're supposed to be fine with being awkward and skinny. I'm very easy to psychoanalyse. I was a gangly, awkward teenager who could make people laugh and thought that was a way to be socially more comfortable' - but also his upbringing. He was raised, he explains, in suburbia with a lower-middle-class mentality, 'Not so much from my parents, but just generally: "It doesn't happen to the likes of you. You're not going to be in a film. You're not going to be on the stage, so why are you even thinking about it?" ' As a result his love life was an early desert - and a lengthy one; a kind of Sahara.

This autumn, he's doing what he can to water the desert. He's putting the finishing touches to the second season of Karl Pilkington's An Idiot Abroad. There's a new sitcom, Life's Too Short, written and produced by Ricky and Stephen and starring dwarf actor Warwick Davis. And he's touring a new stand-up show called Hello Ladies in which he sets out his marrying ambitions and then tells us how to woo - Merchant-style.

'The thing that has always occupied my thoughts more than anything all through my life has been the pursuit of romantic love or sexual conquest,' he explains. 'The music I listened to was related to that, the films I enjoyed, the books I read - and for all the other things I have done as divergence, that's the thing that always comes back to my thoughts. I'm interested in everyone's love life really, from the confident kids to the little couple you see in the pub who've been married for 45 years and aren't really saying anything, just having half a glass of bitter. Because it is just so funny to me, the jeopardy of it, what's at stake, the presumption of it - everything'

Surely, however, he's been in a version of a marriage with Ricky Gervais for the past 14 years? Escaping Weston-super-Mare with dreams of becoming the next John Cleese, Merchant studied film and literature at the University of Warwick before meeting Gervais in 1997 when he applied for a job as his assistant at Xfm. They clicked straight away and they're still essentially two blokes in the pub having fun, although, occasionally, Merchant can sigh at some quirk that he finds annoying. 'Like if I'm really tired and he can't decide on where he wants to eat, I find myself sometimes thinking, "What if, what if?" ' he smiles. 'It's interesting, it's like speculating on alternative universes, but the sad truth is that we sit in a room and there's a lot of hard work. And I'll always come back.'

This, of course, is part of his charm. The Gervais/Merchant experiment grew from joke-telling in the back office of a radio station, through Merchant's trainee BBC job, to the first series of The Office ten years ago and its subsequent global franchising into the US, Germany, France, Israel and even Chile, to follow-up series, movies and enough money that, if he's careful with his spending, he need never work again.

And yet he still seems the odd one out, tapping at the glass of the party and trying to get in. He's got a comfortable house in Hampstead, but the duo still rent an office above an estate agent where they go every day to write. He's a workaholic and film obsessive who worships Woody Allen and Billy Wilder and has surprisingly few vices: he doesn't party, avoids premieres, likes going to restaurants, owns a guitar he keeps trying to learn. In a different life, he thinks, he'd probably have been a teacher, 'like Robin Williams in Dead Poets Society'.

He's a curious mixture, this tall man in ill-fitting clothes. On the one hand he seems very wary. Gervais bounds into rooms and shakes people's hands. Merchant stands back and watches you carefully. You could almost believe he's shy. On the other hand, he's very self-assured when it comes to his work and achievements, perhaps because he decided he wanted to write a sitcom aged 15 and has now out-performed every ambitious target his teen self set out.