Michael Moore: The unlikely pin-up of the Cannes festival

Satirist and Palme d'Or hopeful

There was a time not so long ago when the buzz in Cannes centred around gun-toting American action heroes such as Arnold Schwarzenegger and Sylvester Stallone. Proof that the mood has changed came on Friday when the one unmitigated sensation in the Festival so far was provided by a portly, baseball-capped film-maker from Michigan and his documentary on the American obsession with guns.

Bowling For Colombine, directed by campaigning film-maker and satirist Michael Moore, is the first documentary to be shown in the official Cannes Competition for 46 years. Despite the opening-night appearance by Woody Allen, whose film Hollywood Ending was received at best politely, Moore has turned out to be Cannes's favourite American. He received a 10-minute ovation in the Festival Palais, with calls of "Michael Moore for President". Speaking breathlessly in his car on the way to Saturday morning's round of promotional interviews, Moore – always inseparable from his trademark baseball cap – says, "I came on the stage and I finally had to start talking, just to get the applause to stop. One of the committee people said it had never been that long. I was walking out of the Palais and someone says, 'It's a premiere.' I said, 'I know it's a premiere.' He says, 'no, the applause – it's a premiere, a record'."

Moore's film investigates America's obsession with gun culture and the constitutional right to bear arms, in the wake of tragedies such as the Colombine High School massacre in Littleton, Colorado and the shooting of a young girl by a six-year-old boy in Moore's own home town of Flint, Michigan. The film begins in Moore's characteristically jokey style. But it becomes increasingly chilling and serious with its analysis of an America in which a lucrative weapons trade is fuelled by what Moore calls a "Culture of Fear", an over-emphasis in the media on coverage of violent crime and in particular the scapegoating of the black community. The film includes sequences in which Moore investigates the civilian Michigan Militia, with which Oklahoma bomber Timothy McVeigh trained, and a bank which offers free guns as an incentive to clients.

He also interviews weapons-obsessed teenagers, including one who admits to manufacturing home-made napalm. Rock star Marilyn Manson, widely accused of being an influence on the Colombine killers, makes a lucid and pithy response to the charge. When asked by Moore what he would say to the Colombine killers, he replies, "I wouldn't say anything. I'd listen."

The film is particularly critical of the National Rifle Association – of which Moore himself, an enthusiastic teenage marksman, is still a member – and of the NRA's spokesman, movie star Charlton Heston, who held controversial meetings in Littleton and Flint shortly after the killings there. The film scores two considerable coups. One is Moore's interview with Heston at the star's home, with Heston visibly embarrassed when asked whether he would apologise to the parents of the girl killed in Flint. The other coup is his unannounced visit to the headquarters of major retailer K-Mart, accompanied by two young men seriously wounded at Colombine. Within hours, Moore obtains an undertaking that K-Mart will cease selling guns and ammunition in their stores.

Moore is arguably America's most visible and popular scourge of corporatism and the right – partly because of his brash personal style and no-bullshit regular-Joe persona. A former editor of political magazine Mother Jones, he rose to fame with his 1989 documentary Roger and Me, which he sold his home to finance. In it he investigated the economic and social effects of General Motors' abandonment of Flint, Michigan. Unexpectedly, it won him a $3m deal with Warner Bros and was a major box-office hit.

Moore further developed his aggressive, often stunt-based satire and doorstepping journalism in two television series, TV Nation and the Emmy-winning The Awful Truth. In the wake of 11 September, his publisher Harper-Collins pressured him to rewrite his satirical book Stupid White Men, which is highly critical of the Bush administration, but Moore – with support from a lobby of American librarians – resisted. The book went on to become a bestseller in the US and Britain.

He confesses to being surprised by his film's Cannes reception, particularly because he never even submitted it for competition. "It says on their website, no documentaries – I was obeying the rules. I was hoping to get a little sidebar screening."

He is optimistic about the film's prospects in the US, where it has just been bought for a reported $3m by distributors United Artists, beating bidders including Miramax and Fine Line. "I think it'll be controversial and provocative. From what I've learned about how my book is being received, there's a lot more people wanting to talk about these things. I'm more optimistic than I've been in a long time. People just think that everyone in America is whacked out on this rise of patriotic fervour."

Moore's next project, he says, is about just that topic. "It's tentatively called Fahrenheit 9.11 – the temperature at which freedom burns. I'm not talking about external terrorists. I'm talking about the people who have taken over the White House and are trying to shred our Constitution."