THERE are very few eccentrics left in Hollywood these days - but it would be possible to argue the case that the actor Billy Bob Thornton is one of them.

He has a fear of antiques - worrying when he comes to London because it's full of them - and insists on eating all his food with plastic cutlery, a small supply of which he carries with him wherever he goes.

And, unusually for an actor, he maintains that he cannot endure plays or musical theatre - "I just want to run up on stage and mess up their hair and turn over the furniture".

Taking a seat in the very new Soho Hotel (no antiques, see) at a table with myself and five other journalists to discuss his new film Bad Santa, it's clear to see why he's a man who is liked in Hollywood, receiving his star on the Walk of Fame last month.

After he has carefully placed his American Spirit Cigarettes in front of him and poured a glass of water, he devilishly grins at me for a second and I sense some of the charisma which has procured him five wives, most famously the actress Angelina Jolie.

There's definitely something about those eyes, I think, as he hypnotises me with a shake of his wrists, adorned with heavy silver bracelets, including one with "Hysteric" written on it.

Bad Santa opened last Christmas in America to a big box office, but a critical mauling from some of the more conservative elements. Thornton plays the titular worst-ever department store Father Christmas, one who piddles his pants and drinks excessively on the job, not to mention using the "f" word to the children's faces.

"Growing up we always had a very traditional Christmas and I loved it," he begins in a smiling drawl. "The thing that's most opposite from me about this character is that I love Christmas.

"I have 10 and 11-year-old boys and a one-month-old daughter so it's a really special time and I'm actually quite sentimental about it.

"The thing that might be more similar to me is all of the other stuff that he does! I don't mind a smoke every now and then, and I've been known to take a drink or two.

"My 10-year-old desperately wants to see it - he's the wild one. They were on the set with me and saw me film some of it so they questioned me about it. They knew why they weren't going to be able to see it, but when they get about 15 or 16, then can they see it. Right now, nuh-uh."

And as for his baby girl?

"Oh she can see it any time she likes! Here's the thing about the movie. It came out last Christmas and was hugely successful, the most critically-acclaimed comedy of last year. Insane. We couldn't believe it.

"My guess was that the journalists would love the movie because they tend to like dark comedies and things like that. Normally, if you see a bad review on a Christmas movie, it's on some real syrupy schmaltzy one.

"What we were surprised about was the fact that it was a movie targeted towards a particular demographic, but the audience were from all over the map. There were teenagers there and 80-year-old women and I was like 'Wow, this is cool'. As a result it made a lot of money.

"There were individuals offended by it, from the religious right, and we did get a few comments from some of them and my reply to that is, as far as I know, Santa Claus is not in the Bible. I was like, 'I think you guys are talking about Jesus'. Maybe we should make a Bad Jesus."

Billy's main co-star in the movie is 11-year-old Brett Kelly, a very tubby and impressionable young man who seems to take it into his head that Billy's character is the real Santa. Did he have any concerns about behaving the way he did in front of a kid?

"Brett is very sweet, not a lot different than he is in the movie, and he's kinda innocent like that. He will just look at you. But he was a really good kid and I never had a problem.

"Before we started the movie, I was a little nervous, but when I got there, those kids were so nonplussed - nowadays kids are more exposed, they watch South Park and stuff like that. If we made it 20 years ago, it would have been a little bit different.

"Also, when you're playing a character, you have to absolutely go into it. You can't be sorta drunk. You have to forget that that's not really the way you really are.

"I love children, I'm crazy about them and I just had to ignore that fact and play the part to the max. If you put a knife in someone, you've got to twist it a time or two.

"I would have trouble sometimes with Tony Cox, his diminutive co-star who plays Santa's elf because he's such a nice guy. Seriously, the guy couldn't get mad. He doesn't have a bad bone in his body and in the first few scenes he shot, he just wasn't getting it.

"His wife is a regular-sized gal and so I would hit on her sometimes and I would tell him about it and he'd get mad then and we'd do the scene! We'd have a great laugh about it. He's one of the greatest people and just so funny.

"It's like John Cusack and I always have a mind game thing going on. I love John and we have a new movie coming out together. I will always wind people up a little bit. You gotta mess with people to get the most out of them. You can even mess with journalists a little too. Like I had a blood vial!" he laughs, referring to the tabloid reporting of his and Jolie's relationship.

Coming off the back of The Alamo, in which he played Davy Crockett, the move to Bad Santa seems to typify Billy's career in the sense that he can seemingly inhabit totally different personas without much difficulty.

Does he find it easy to make these switches?

"I find training has very little to do with acting. If you think about it logically, how could you teach someone to do something creative?

"What I've always done, through drama in high school, it's really just something I have done since I was a kid. I have really worked from the inside out as opposed to some actors who start with the look and then the look tells them what to do in terms of their emotions.

"When I read a script, I know what the character looks like. It's like when you're reading a novel and you get an idea in your head of what everybody's like. Sometimes it's weird though because I know what I think they're like, but, when they cast different people, you have to adjust!

"Since I played the guy in Monster's Ball, where he and Halle Berry share a very torrid love scene every black guy in America, I'm his hero. I go through the airport and all the big security guys are like, 'Hey Billy Bob, Halle Berry, man, Halle Berry'.

"And playing the president in Love Actually was the first time I shot a movie outside of North America. I'm not much of a traveller but, in terms of movies, if they say we're doing a movie in the jungle or North America, I usually just say, 'I'm tired'. I try to stick close to home because of the kids."

How is he finding fatherhood again as he approaches his 50th birthday?

"This is a girl so it's a different feeling. My girlfriend has never had a baby, this is her first, so I find myself saying, 'Honey, here's the way you do this'. I've learned you don't have to get hysterical.

"With my daughter Bella I have a certain calm about me. Like when she cries, my girlfriend freaks out, but I'm like, 'She's just got gas'. It's amazing how kids can give you peace.

"For me, if I go home at night and I'm stressed out, I come home and get in the rocking chair, put on the baseball game and have the baby there.

"I felt 50 20 years ago! I'm not worried about it.

"Frankly, my success has taken place in my later life, so these are the good days."

Bad Santa is on general release now.