Happiness director Todd Solondz is back, pushing the envelope as always with Palindromes. The story of a troubled and pregnant 12-year-old girl as portrayed by eight different actors manages to say something both eloquent and disturbing about contemporary America, writes Michael Dwyer.

Palindromes, the characteristically provocative new film from US writer-director Todd Solondz, opens with the words, "In loving memory of Dawn Weiner", a reference to the troubled teen heroine of Solandz's 1995 breakthrough, Welcome to the Dollhouse. This suggests that Solondz is putting his preoccupation with adolescent anxieties behind him. Not so, we soon realise.

Enter the palindromically-named young Aviva, who is pregnant. Her urge to have a child is thwarted by her loving but steely mother, who insists she has an abortion. Running away from home and pretending her parents were "vaporised" in the September 11th attacks, Aviva is taken into a refuge run by a Christian fundamentalist named Mama Sunshine and populated by disabled children.

As ever, Solondz challenges the viewer through the themes he tackles and his treatment of them - and this time in his high-risk casting of Aviva with eight actors of different age and race, one of them a boy and another played by Jennifer Jason Leigh.

"I expected that the audience would feel confused at first, but at a certain point I felt it would become clear what was going on," Solondz said over a late breakfast of porridge when we met at the London club, Soho House. "I believe audiences will accept rules, no matter how strange they are, provided you stick to the convention that is set up.

"All sorts of people came up to me after they saw Welcome to the Dollhouse. It could be a beautiful model or a heavy-set construction worker. It didn't matter. They all said the same thing: 'That was me. I was Dawn Weiner.' They could all make that identification.

"So I decided to do something different, where everyone can experience the movie through the filter that is Aviva. This movie is a fable of sorts, a fable of innocence. So when she is released out into the world and escapes from home, she finds this other family and she becomes this big black woman. The idea in my head was that she would become a kind of Gulliver surrounded by these Lilliputians.

"At the end, when you see Jennifer Jason Leigh's face, it's like in a fairytale, as if this character had lived a whole life. You can read from Jennifer's face, as a woman of a certain age, that Aviva has been through so much. At the same time she's still 12 years old.

"Getting all these different colours and qualities from each of these actors hopefully has a cumulative effect that's greater and more affecting emotionally than had it been just one young girl in the role.

"When I cast a movie," Solondz says. "I often have, say, three actors who are good for a part and each has different qualities. I tend to fantasise about what I could get if I could combine all three. There is a scene in the movie where Mark Weiner, Dawn's brother, says that it doesn't matter if you're 13 or 50, if you've gained or lost a lot of weight, or even had a sex-change operation, you will still be essentially the same person underneath that appearance.

"So after all these metamorphoses, Aviva remains an innocent, despite all the disturbing or morally troubling adventures she has been through. She remains the same - like a palindrome, which, instead of developing in different directions, just folds in on itself. The beginning and the end are the same.

"In a loosely metaphorical sense, we are palindromic in the sense that there is a core to each of us that does not change, no matter what sorrows or joys we experience in life. There is, of course, constant change, but there are certain things that we can never change about ourselves. Mark Weiner sees this with a certain doom, but I see it more benevolently. I believe if one acknowledges and embraces one's flaws and one's limitations, that it can be liberating."

Now 45, Solondz seems much more assured and expansive in conversation than when we met seven years ago. Then, his powerfully confrontational Happiness had its first screening at the Toronto Film Festival and he appeared understandably anxious about how that taboo-breaking movie would be received.

Palindromes deals directly with strongly held stances for and against abortion, which, I note, continues to be such a divisive issue in many countries. "Like Ireland?" he asks. "And even more so in the United States," I reply. "That's true," he says. "I don't want to state my position, whether I'm pro-choice or pro-life, because I don't want the audience to say: 'Oh, it's all right. He's pro-choice, so it's okay, I can watch it.' I don't want to let them off the hook.

"It's easy enough to take a position, but to really examine and understand the consequences, the ramifications and the moral dimension of what it means is something much more difficult. It's something the film asks of us. The debate, in as much as it exists in the United States at least, is so degraded. It's all slogans. There's a demonising of each other from both sides."

Yes, but the pro-choice side doesn't kill people on the other side.

"The pro-lifers have been waging a war," Solondz says. "It is a war, and abortionists have been bombed and killed. To my mind, just as policemen and firemen are heroes, so are abortionists, in so far as they put themselves on the line - even though they could make a good living providing other medical services and upsetting nobody."

He says he had no interest in making a movie that was clearly for or against abortion. "It's like making an anti-war movie. Even though many of them have been wonderful, I don't believe any ever stopped a war from happening.

"Michael Moore made Fahrenheit 9/11, but did it change anyone's mind? I tend to think those of the liberal persuasion agreed with it, but the others can look at the scene of Bush reading My Pet Goat and believe he's being thoughtful and that he's deliberating. We bring our own prejudices to everything we see. It's something of a vanity to imagine you're going to change the world with a film or a book."

In Palindromes, there is a startling bluntness about the mother's insistence that Aviva have an abortion. The mother is not a terrible person, Solondz believes, but she makes a terrible mistake.

"She doesn't handle the crisis in an appropriate way. Later, when she asks if she is a terrible mother, I think it's a question every mother asks at some point. Every mother probably thinks they could have been better. In that scene she's acknowledging her failure to come through for her daughter at a critical moment, and I think therein lies her dignity, in that recognition of failure, and that's moving. How many parents are fully equipped and prepared to deal with a situation where their 12-year-old daughter tells them she is pregnant?"

As the mother, Ellen Barkin is on prime form, seizing on her meatiest role in a long time. Solondz observes that Barkin certainly didn't make the movie for the salary he could offer her, considering that her husband, Ron Perelman, is a billionaire, the owner of Revlon.

"In fact it costs her more money to be in the movie because she came in on the set every day by helicopter with her entourage of hair, make-up and security people, and this was all at her own expense. This little movie was made for under a million dollars, but she was such a trouper. She was really happy to be involved with something that she felt was worthwhile."

Solondz regards the home run by the fundamentalist Mama Sunshine as the inverse of Aviva's family in the film. "You have the conservative Christians and the progressive liberals, liberal Jews in this case. It's like Bush and Kerry, the religious and the secular. America is so polarised at this stage.

"We all have our prejudices, and liberal audiences may well regard Mama Sunshine's family as strange and bizarre. You can laugh at them, but it will be somewhat hollow laughter in the end because you have to admit that it's a beautiful family. What could be more generous or virtuous than doing what Mama Sunshine does by providing these children with the sanctuary of a caring, loving family?"

Solondz accepts that there is a satirical thrust to his movie, but insists it is much harder on liberals than on conservatives. "If I was going to err, I wanted to err on the side of the conservative Christians. I wanted people to be unsure if this was a pro-life movie or not. I didn't want it to be too easy. Easiness is just comforting the audience.

"If I didn't have an emotional connection with the characters in my movies, I wouldn't make those movies. It's just too hard to go through this process otherwise. It's funny, because some people look at my movies and describe me as cynical, hateful and misanthropic. I think that's a very reductive way of looking at those movies. But if you don't like something, you'll throw everything you can grab at it. I'm not out to polarise, but maybe it's a result of portraying the world as I see it."

Given the candour with which Solondz has expressed his view of the world in his movies, he appears most unlikely ever to follow all the many US directors who started out in independent productions and sold out to the Hollywood studios. He responds to this observation with the satisfied smile of someone passing on a big secret: Drew Barrymore had talked to him about directing Charlie's Angels, which she co-produced.

"I loved the idea of taking these icons and having a lot of fun with them. But I also knew no studio would ever hire me for it because if I did it my way, the film probably wouldn't have made more than $3 million - instead of the $300 it made. My movie would have been a little art movie with Charlie's Angels in it. So that was the closest I've come to ever doing a studio picture, although Drew was really into it.

"The fact that I've even made Palindromes is amazing and gratifying because I've put these things out there to provoke, but not in a cheap way. After all, these subjects are on TV every day of the week, but usually in a sensationalist or moralistic or didactic form. I like my movies to be more exploratory and I try to understand these people and these issues.

"If I grew up in a different background, I could see myself getting a gun and shooting an abortionist. That's my job, to imagine what could happen, what can make people go in different directions. I don't have any illusions about America. I live in New York, but New York is not America."

Palindromes opens today and is reviewed online in today's Ticket