Interview: David Walliams

On one hand, he refuses - today, at least - to talk about his personal life and marriage to supermodel Lara Stone, 26.

"That's something that's not in the remit of this interview," he declares, when asked how married life is treating him. Fair enough.

He's entitled to his privacy, even if he has talked at length about his and his young wife's life in a recent issue of Heat magazine.

When it comes to his books, Walliams, 39, does not like to be labelled a celebrity author lumped together with the likes of Katie Price, although being famous must surely not have harmed sales of his children's books or the promotion of his latest, Billionaire Boy.

He makes rare appearances on the literary festival circuit, having done Cheltenham Festival last year, and his first two books have been nominated for the Roald Dahl Funny Prize, so it probably won't be long before he's a regular at literary events or has become a Booker judge.

"There's still some snobbery," he reflects. "Sometimes I'm linked as a celebrity author when newspapers write, 'Celebrity authors like Jordan and David Walliams...' Hang on! I've written a successful comedy show.

I don't feel like I should be demoted to a celebrity author.

"I'm a celebrity because I'm a successful writer and actor. I wasn't on Big Brother."

There are those who would argue that there are lots of writers out there who haven't been published because their name isn't known.

"But then I was at one point an unknown writer who was trying to get a comedy show on Radio 4, so I've been in that situation," he points out. "I don't feel like being an author is some career I shouldn't have had. I don't feel like a fraud.

"In the book publishing world, I would imagine that some of the more high-profile books end up paying for some of the less high-profile ones."

High profile he certainly is - he and his Dutch wife are all over the place, on adverts, magazine covers, in newspaper gossip columns.

What does Lara think of his books? "She likes them - but I don't know if she'd say if she didn't like them," he laughs. "But I don't let people read the books until after they've gone to the publisher's, so it would be too late if she thought I ought to change something."

He reads his reviews and is quick to note that his two previous children's books, The Boy In The Dress and Mr Stink, were extremely well received.

His third book, Billionaire Boy, aimed at nine-to-12-year-olds, is another entertaining and witty read about a fat, lonely 12-year-old, Joe Spud, the richest boy in the world.

The story follows his adventures at secondary school as he is bullied, finds a new pal and then dumps him for a pretty girl who isn't all she seems.

It does, however, have a happy ending and an underlying moral that money doesn't buy happiness.

The book isn't autobiographical, says Walliams, but there are parts of it that are personal and he says he wouldn't have written it had he not become rich and famous and had the experience of how people's behaviour towards you changes when you become wealthy. And the message is important, he notes.

"It seems that kids are increasingly interested in money and fame. Things today can happen quickly through television. You could be completely unknown, then appear on Big Brother and two months later people know who you are and you can be making money out of magazines.

Kids think that people can wave a magic wand and make you rich and famous."

Switching from writing for adults to writing for kids has been difficult, he admits.

"Little Britain was a show meant for adults but kids liked it, just as I liked things when I was a kid that were a bit forbidden for me, like Not The Nine O'Clock News.

"I know the children's books can't go to the places that Little Britain goes, but I still wanted them to have a sense of naughtiness and pushing the boundaries. They're a little bit rude but not terrible."

• Billionaire Boy by David Walliams, is published by HarperCollins, 12.99