A big tobacco lobbyist is the brazenly un-PC new comedy. But is there more smoke than fire in the film's satire? Jason Reitman, Thank You for Smoking's debuting director, talks to Donald Clarke

JASON Reitman's Thank You for Smoking, a comedy dealing with misbehaviour among those lobbying for the US tobacco industry, is a very funny piece of work. But what exactly is it trying to say?

Nick Nayor, played with glib self-confidence by Aaron Eckhart, is shameless in his efforts to promote his employer's products. He investigates the possibility of paying a Hollywood producer to feature cigarette smoking in a science fiction film. He presses a suitcase full of money on a former Marlboro Man, who is now dying of lung cancer. Yet, somehow or other, Naylor remains the film's hero.

Unlike the plague-on-both-your-houses comedy of the South Park team, Thank You for Smoking is oddly restrained in its satire. Big Tobacco, a target of some considerable breadth, is inevitably struck by a few fusillades, but the film, based on a sharp novel by Christopher Buckley, barely engages with Naylor's motivations. By the film's close we are no closer to understanding where exactly Buckley and director Reitman stand.

"I can help you with that," the perky young director says. "I'm sure there are immoral smoking lobbyists. There are moral lobbyists too. He is not pushing smoking. He is pushing the freedom to smoke, and I think there is a fair argument for that. It isn't the government's job to be parenting us."

Well, maybe. But Naylor devotes most of his energy to opposing health warnings and finding insidious new ways of marketing cigarettes. The issue of outright prohibition is barely raised. Jason, the son of director Ivan Ghostbusters Reitman, has clearly had this conversation before.

"I am not sure how it is in Ireland or the United Kingdom," he says, "but there has been a big change in the United States since Big Tobacco was forced into a financial settlement in 1998. They have been forced into claiming that tobacco is just one the many things they do. They have, reasonably enough, pointed out that, though cigarettes do cause heart attacks, so does junk food. How many more people do hamburgers kill?"

None of which answers the question. But Reitman's comments do go some way towards confirming suspicions that the film may be coming at us from right-of-centre. After all, Christopher Buckley, besides being a former speechwriter for George Bush Sr, is the son of the formidable conservative commentator William F Buckley.

"Here we go. You judge a man by his parents," Reitman laughs. "As the child of a famous father I object to that. But I don't think that Chris has a right-wing mind. I think he has a libertarian mind, which I have learnt means something a little different in Europe to what it means in America."

Yes, indeed. Many here see libertarians as Republicans without the Creationist, fundamentalist baggage. Certainly, given half a chance, Reitman will take the opportunity to mouth off about political correctness. In truth, when set beside the aforementioned South Park - and, in particular, that programme's demolition of self-righteous anti-smoking campaigners - Thank You for Smoking contains little to upset the PC commissars. Indeed, Reitman's decision to have none of his characters actually smoke on screen suggests he may have given in to the new puritans.

"I think it's a tricky decision, but it didn't come down to a question of political correctness," says Reitman (a non-smoker, since you ask). "We did a lot of things in this movie that were very un-PC. But look. Is this a movie about smoking? I don't think so. It is a film looking at the difficulty people get into when they try to tell others what to do. If we showed people smoking then, because you see that so rarely in films these days, then that is all you would see. You would think either, oh, he is saying how horrible these smokers are, or, look he's encouraging us to smoke."

We should, perhaps, not get ourselves into contortions working out where Reitman's film stands. Despite its political opaqueness, Thank You for Smoking remains a fast-moving, witty romp. When you consider that the director doesn't turn 30 until next year, his achievement seems all the more notable.

Jason admits that it was pretty daunting having to direct such actors as Robert Duvall and William H Macy in his first feature. It must, however, have helped that he has been hanging around movie sets since he was a toddler. Ivan Reitman, one of the most commercially successful directors of the 1980s, was responsible for Stripes, Ghostbusters and all those high-concept comedies in which Arnold Schwarzenegger got pregnant or had a shorter, fatter twin.

"Well, a set is really no place to make a film," Jason jokes. "You have 100 people looking at you at all times. So, yes, it was helpful that I had been on sets since I was a kid. I remember being on the set of Ghostbusters in New York City. I remember they blew up an entire street and I thought, yes, now this a great job. You can do whatever you like."

Are their downsides to having a father in the business? Does he ever fear he might not get out from under Ivan's shadow? "The downside is people presume the worst of you," he says. "They assume you are not intelligent. You are a snob. You are a spoiled brat. If you do find some success, it is perceived to be undeserved."

Despite his early enthusiasm for the movies, Jason did not go to film school. But by his sophomore year at the University of Southern California, where he studied English, the younger Reitman was already making low-budget shorts. At 19, Operation, his film about organ theft, premiered at the Sundance Film Festival. "Most young kids dream about making their speech at the Oscars. I dreamt about appearing at Sundance."

Thank You for Smoking has been Reitman's dream venture for half a decade. For some years Mel Gibson's production company fiddled around with the project, but they could never attract the interest of a studio. Eventually Reitman ran into David O Saks, a young multimillionaire who made his fortune devising PayPal, a mechanism for enabling credit-card payments over the internet. Saks financed the film out of his own deep pockets and Fox Searchlight later picked the film up for distribution after it premiered at Sundance.

"Saks is a libertarian guy himself," Reitman explains. "And he published a book on that subject when he was at Stanford. He simply couldn't understand why the film hadn't been made yet. So, he put up the entire six and a half million dollars himself. He had made a fortune when he was in his twenties, so he was prepared to take chance on a young, fairly untried film-maker. He understood."

Interesting. So Saks had some kind of political agenda. This is where we came in. What did the entrepreneur want to say about the tobacco lobbyists? "Well. We don't see them as evil," Reitman says. "They didn't set out to kill people. Look, if these guys had grown up in Detroit they might be working for Ford. If they had grown up in Atlanta they might have worked for Coke. They grew up in Winston-Salem, so they work for the tobacco industry."

Maybe if they'd grown up in Cambodia they might have worked for the Khmer Rouge.

"Oh well that's going a bit far," Jason prickles.

Is it? For a self-proclaimed satirist he seems a very reluctant to stick the knife in.

Thank You for Smoking opens today