In 1986, jobbing comedian Jimmy Mulville set up the TV company that made 'Father Ted' and a string of other hits. He has just sold his share for €15 million, writes Esther Addley

Jimmy Mulville doesn't really do interviews. He usually leaves them to his business partner, Denise O'Donoghue. "People tend to be more interested in her anyway, because she's a really successful businesswoman, and, you know, very attractive. She's always cropping up in those lists of most-successful women. Whereas with me . . ." He trails off with a little shrug that isn't rude but isn't terribly warm, as if to say: I don't really know why you're here.

Although he does, of course. Two weeks ago Mulville and O'Donoghue pocketed £11 million (€15 million) each when they sold a little less than half of Hat Trick, the British TV production company they founded together 17 years ago, to a venture-capital firm. In an industry of pretty wealthy players it has made them extremely wealthy players, although the pair have been weighty figures in telly for close to two decades.

The company behind a wet-dream roster that includes Have I Got News For You, Whose Line Is It Anyway?, Father Ted, Drop The Dead Donkey and The Kumars At Number 42, Hat Trick was the first independent producer to win a BAFTA (for Whose Line); it has now won more awards than any other non-BBC producer in the history of British broadcasting. In 1999 Mulville and O'Donoghue were given the BAFTA Alan Clarke award for outstanding contribution to television. They may have gathered themselves a potload of cash, but the pair have a fair claim to have changed British television in the process.

"I suppose, yes, the night Denise and I signed the deal we did have a moment when we felt really, really proud of ourselves," says Mulville, permitting himself a small smile. "I mean, I'm the son of a waitress and a bloke who used to work in a factory on the Dock Road [in Liverpool]. We set this thing up with no expectations, and nearly 20 years later these two people who have been through quite a bit . . . . Well, we sat in a restaurant and thought: 'You know what? We've done well.' It was a nice feeling."

It was certainly an adventure. When the pair set up the company, Mulville was a 31-year-old jobbing comedian, an alcoholic and an enthusiastic user of cocaine; O'Donoghue was a former management consultant who had moved on to work with independent programme producers. The pair were also married to each other. In their 17 years establishing themselves as one of the most formidable duos in the media, the pair have divorced and Mulville has beaten his addictions, remarried and had a family (aged three, four and 13, "and another on the way").

How on earth did they do it?

"Slowly . . . I think. When Denise and I separated, neither of us wanted to leave the company, so we had to renegotiate. And we've managed that, and I'm pleased that we did. Because you wind up in business with somebody you can pretty much trust because, well, you've been married to them for 10 years, and you've certainly been round the block with them." Do they themselves see it as an exceptional arrangement? "Yeah. I think we do. Mutually, I think it is one of our proudest achievements."

Hat Trick was initially established to produce Chelmsford 123, a radio programme Mulville had written with Rory McGrath, a friend from Cambridge University's Footlights (other college friends, in what must have been a remarkable social circle, included Griff Rhys Jones, Clive Anderson, Stephen Fry, Emma Thompson and Nicholas Hytner, now artistic director of the National Theatre). Mulville later took part in a radio version of Whose Line Is It Anyway? and thought it was a fantastic idea.

"So Denise and I met Dan Patterson, the producer, and said, 'How do you feel about doing this on TV?' This was a time when Channel 4, which was very new, was wide open to new ideas. We pitched to Michael Grade [then chief executive of C4], he said, 'Great!' and commissioned a series of 12. And that was our first hit, really. And what happened in terms of my own career was that I became much more absorbed with what was happening here than with me doing the odd sitcom - which I could still be doing and be quite happy doing - but the thing is, you have to make choices. My career was going moderately well, I was in five TV series and a play at the National during my supposedly unsuccessful career, but it felt much more absorbing to get involved with what was happening here."

If he sounds a little sore on this point, it is because the story that has attached itself to Mulville, doubtless exacerbated by the greater celebrity of his early friends, is that he essentially couldn't cut it as a comic and so had to go into production. It's a curiously mean-spirited reaction to someone who went on to be so spectacularly successful elsewhere, but for Mulville it is clear that the charge still stings. "I didn't realise I was being so unsuccessful as the press have since decided I was. When we did the transaction, the Evening Standard had the headline 'Failed comic and ex-wife make 23 million quid' . . . . Typical of them to snatch defeat from the jaws of success."

Hat Trick was 18 months old when Mulville went into a treatment centre. "In December it will be 15 years. Complete abstinence. Can't believe it really." Not that his sober nature, at 48, is much different, he says. "Oh no. I'm a f---ing workaholic now. I'm obsessive. When I ask for tea and biscuits, I don't mean one cup of tea and a biscuit, I mean a pot of tea and a packet of biscuits, and the pot of tea is drunk and the packet of biscuits is eaten. I tend to eat until I am slightly sick."

To fall for his appearance as a twinkly-eyed genial Scouser would be an error; Mulville still has an edge that could sharpen scimitars. "I try to hold to the G. K. Chesterton comment that a gentleman is never unintentionally rude. So when I'm rude I really try and mean it. I try to get the person right between the eyes. No, I can certainly defend myself."

But this, he insists, is part of what has got them where they are. "When we started nobody really wanted an independent company to be in existence, certainly not the BBC and ITV. And in order to teach someone who wants to treat you badly to treat you well, you have to not give them what they want."

They are finally in a position where they can be more "consensual" with the broadcasters, he says. "I always used to see the BBC as some terrible paternal figure that I was always having to rebel against, when now I'm actually older than most of the people I deal with there. Let's face it, if I was still playing the enfant terrible it would just be terrible, because I'm not an enfant any more. I suppose you have to grow up a bit."