"That's been known to happen, but whoever I am, I'm not the guy you want babysitting your kids.

There's a certain age of kids I don't like. I don't do googy-goo-goo-goo.

I prefer little girls because they like being treated like adults."

Allen never wanted the Santa job. Disney kept pushing until he agreed to play the title role in The Santa Clause in 1994. He empathised with his character, a workaholic advertising executive who hadn't been giving enough time to his family until Santa fell off his roof and was incapacitated, and . . . out of guilt . . . he jumped onto the sleigh himself rather than spoil every child's Christmas. "And now three movies later we're both stuck with it, " he shrugs.

That's Hollywood for you. With The Santa Clause a surprise hit, he was catapulted from the TV comedy Home Improvement to everyone's favourite Santa, particularly Disney's. "I didn't want to do Santa Clause 2, " he says. "I didn't want to do Santa Clause 3, either. Nor did I want to come into this room to talk to you. But I did. Because this is the kind of person I am."

We're in the Regency Hotel in New York. Already the windows glitter with Christmas displays.

"Christmas has become basically a shopping festival. Halloween is worse. It starts in June and it's become bigger than Christmas, almost." In Santa Clause 3, Jack Frost usurps Santa and turns the North Pole into a gigantic theme park where the measure of how much you love your children is the amount of money you spend on them. "We're parodying what has happened to Christmas, " he says.

"But I wouldn't write it off yet. It's still a time when people get in a better mood, particularly in small suburban communities like where I grew up in Denver. Hearts open up a little bit. As long as that stays, there'll still be Christmas. All the consumerism is unfortunate, but that's what America is."

What bothers Allen about being mistaken for Santa is all the questions. "When I was dressed as Santa these children on the set in Toronto really believed. They'd ask things like where do the elves eat and it was a really weird responsibility for me because whatever I said they were going to carry through life. Of course in Los Angeles the kids were terrible.

This kid was going, 'He's not Santa, he's the Home Improvement guy.'

There's always one kid that will wreck it for the rest."

His father was an insurance salesman. "He died in a car accident when I was 11. He always did these wonderful Christmases you remember. We'd get none of the things we'd asked for and then he'd say, 'I think Santa left something outside, ' and it would be like baseball gloves, always the big thing you never thought you'd get."

Allen's mother remarried to an Episcopalian deacon when he was 13. "He was different to my father.

He didn't like cars. He was the dad I grew up with. He provided stability. Because I didn't have my own dad I was always at other kids' homes looking at theirs. When you don't have one of your own they all look pretty good. I think probably out of that background I have always liked playing dads like how I visualise my dad was."

Allen realised he could make people laugh when he was at elementary. "I was kicked out of school once for being funny. They said I had behavioural problems.

My parents were appalled. 'It's because you don't listen, ' they said.

'You're always trying to be funny.'" While at college he did stand-up for a dare at a nightclub in Detroit and soon became a regular at the city's Comedy Store. Moving to LA he was one of the so-called "dirtydozen", a group of stand-up comedians popular for adult humour. If humour is the unexpected collision of opposites, Disney's reinvention of Allen as Santa Claus is its ultimate expression. In 1978 he was arrested for possession of over a pound of cocaine and served two years in prison. Yet now he runs his own production company within Disney, "We're kind of outsiders on the inside. We feed them ideas.

He's already remade the 1959 comedy The Shaggy Dog, casting himself as an attorney who's turned into a dog, running around finding out what his children really think.

"There are a lot of old Disney projects that weren't mined enough.

There's gold there."

So what does his 17-year-old daughter . . . by his first marriage, he married again last month . . .

think of him? "I don't want to know, " he says. "One moment she loves me, the next I'm the worst in the world. It's a really odd age."

He's had his differences with Disney, particularly over his insistence on improvising his performance on camera. "I tell them to give me a start and what I have to end with and just let the camera follow me because I can't say what I'm going to do. People still don't get it. They don't quite trust it. I don't. I don't know where it comes from or what happens if I don't think of something. A comedian is not like an actor. If you don't feel stupid you're not getting it out.

You commit to it and finish it and then don't apologise for it."

Allen likes to play jokes on the set. "I got Alan Arkin laughing so hard before a scene in The Santa Clause 3 he fluffed his lines. For him acting is a profession, not a tutti frutti deal like me. So eventually he said, in a nice way, 'Is there a moment somewhere you will SHUT UP?' What saves me in movies is that I'm a comedian so I don't take it very seriously. Even at my father's funeral I was making jokes. The whole thing was an illusion, a lot of crap. If the creator is such a sweetheart, why does he do things like that? I went to St Jude's hospital the other day and I saw little kids of eight with terminal cancer. I'm religious, but conflicted. Why do they suffer? I feel helpless over Iraq. I turn on the news and it's always about fear. I asked an Episcopal minister what Katrina was all about. It's just an opportunity for you to help, she said.

That's all."

He'll next be seen in Zoom as a former superhero called back to pass on his knowledge to a ragbag group of children. He's just finished Wild Hogs, which revolves around a group of frustrated middle-aged suburban wannabe bikers who run up against a group of real Hells Angels. "Acting has given me a way of expressing myself. As much as I like this, I'm embarrassed by the attention even though I crave it. I do this to get acceptance but then when people enjoy what I do I get embarrassed.

I don't feel I deserve it."

'The Santa Clause 3: The Escape Clause' opens on Friday