When Lee Mack was writing the first series of his sitcom Not Going Out, the walls resounded every day to the sound of happy laughter. But it wasn’t him or his co-writer Andrew Collins who were clutching their sides. In the office next door, the comics Matt Holness and [[ Richard Ayoade were writing their spoof chat show Man to Man with Dean Learner. And while the two former Footlights members cracked each other up with improvised ideas, Mack and Collins worked their way forensically through their scripts, never moving on until Mack was convinced that they had each line right. A year later, Not Going Out has just finished its second series, with a Christmas special and a third series to come. Glittering with gags, and boasting wise-cracking characters in metropolitan settings, it’s nowhere near the cutting edge. But, unlike almost every other sitcom, it’s thick with good one-liners. Meanwhile, Man to Man... – despite some inspired moments – never got beyond a first series that was surely more fun to write than it was to watch.

Now Mack, 39, is back touring, a bigger draw than ever. It’s nice to be back out, he says, after spending most of the year at his writing desk. Mack’s persona may be blokey, blithe and irreverent: “I’m in a relationship at the moment. Sorry, girls – it’s going to have to be your place.” But it’s the way he refuses to coast on his charm that keeps his silliness splendid.

“Not Going Out is quite an American style of show,” says Mack, over sausages and mash (ah, so unpretentious) at his local caff (er, Hampton Court Palace). “There’s a job to be done and you have to get on with loads of jokes.” Mack claims to be under no illusions that he is a great writer. “I do it,” he says, “because there aren’t that many people out there who know how to write a sitcom.”

In Not Going Out, Mack plays Lee – “I’m a bit 50-50 whether to call myself an actor” – a cheeky Northern layabout who ends up sharing a fancy open-plan Thames-side apartment. It’s fast, funny and unburdened by significance. And in his stand-up, he’s an observational comic who will undercut anecdotes by reminding us he’s just making it all up. This is not comedy as therapy. Even meeting close to the home he shares with his wife, Tara, and their boys Arlo, 3, and Louise, 1, unsettles him.

“There are two distinct worlds for me,” he says, “my home life and my professional life. I wouldn’t mention my kids’ names on stage. Well, unless it was a really good joke. And I’d never do a gig in my home town, Southport [in Lancashire], because it’s full of my relatives and friends.”

It’s an old-fashioned approach – I’m a comedian, here are my jokes. But Mack makes it personal with the acuteness of his observations and the physicality of the performance. Puffing his chest out like Robbie Wil-liams, stuttering like Hugh Grant or staggering like a bad Olympic gymnast, he’s full of irony, but he’s never diffident about his delivery.

“It’s easy to get self-indulgent in this job. Some comedians forget that there’s a whole world out there of people who have never heard of you. Every time I go on stage I assume that 90 per cent of my audience have never seen me live before. It’s like a one-off opportunity to say to these people, I’ll be coming back next year, so if you want to see the show...”

Mack – real name McKillop – grew up above a pub in Blackport, Lancashire, before his parents split up when he was 12. Then, after a few years as the class clown in Southport – “Sooner or later,” read a school report, “Lee will realise that joking around in class will get him nowhere in life” – he worked in a bingo hall, as a stable boy, and then as a bluecoat at a Pontin’s holiday camp on the south coast. He loved being a bluecoat, but his first attempt at stand-up comedy there was a catastrophe.

“I used to work the lights and sound in the ‘adult room’,” he says, “watching all the comics do their so-called blue material. And I thought, how hard can this be? They all shared the same jokes – including the one where you would say to someone, ‘Where are you from?’, they would say ‘Kent’, and you would say, ‘What did you call me?!’ It would always get a laugh.”

Not for Mack. He got drunk one night and went on stage. “And just completely blew it. I said, ‘Anyone in from Kent?’ To which a whole gang of people said yes. I went, ‘You’re all a bunch of c***s, aren’t you?’” He was sacked the next day.

After various further jobs, including being a mobile DJ, he did his first open-mike slot in 1994, while he was studying at Brunel Univeristy. Within 18 months he was a full-time comedian. But he only truly came into his own when he realised that preparation was everything. “It soon dawned on me that this is like any other job. There was some truth in what my teacher said.” He took a show to Edin-burgh; it was nominated for a Perrier. He co-starred in ITV’s The Sketch Show. He hosted the final series of They Think It’s All Over. He’s a team captain on the BBC panel show Would I Lie To You?. “Getting my head round the hard-work factor,” he says, “is why I think I’m doing all right.” Mack has no time for comedy’s claims to seriousness. “All my comedy heroes have in no way influenced me politically,” he says, “or even made me see things from a different perspective. Tommy Cooper and Eric Morecambe have never done anything with any semblance of, you know, this is the way you should look at life.” Operating without the safety net of art, he knows there is no excuse for not being a master craftsman. He wants Not Going Out to run and run. He adores comedy. But he doesn’t confuse it with life.

“I often hear people saying ‘it’s better than sex, the best thing ever’, and I think, I’m missing out on something. I was at an awards ceremony with Jimmy Carr, and Bruce Forsyth was there at a different table. Jimmy pointed over to Bruce and said, ‘It’s a great job, isn’t it, because this is something we could be doing in our seventies, like Bruce.’ And I remember thinking, ‘Oh Christ, you’re joking, aren’t you?’ I don’t think I want that. To me, it’s a job, a really great job, and like any job there will come a point when you’ll want to do some gardening instead.”

Lee Mack Live is out on DVD on Monday. Series one of Not Going Out is also out on DVD. For tour details visit www.leemacklive.com

Editor's choice

• U2 at Nou Camp Stadium, Barcelona
• The 50 Best Movie Villains
• The 15 golden rules of theatre etiquette