Body politics

It's like a scene out of some warped version of Hamlet. Floating face down in the Clyde, her long hair stretched out in front of her, is the body of a woman clad only in a negligee. Two bargemen stretch out with their boathook for this latter-day Ophelia and pull her up. Her white, glabrous body, stretched out on the grimy deck of the barge as it wends its way downriver, past factories and shipyards, looks eerily and incongruously beautiful. When one of the men lays his hand lovingly on the woman's back, we can't tell whether he's saddened or aroused.

This is a key moment from David Mackenzie's new film, Young Adam, adapted from Alexander Trocchi's 1954 novel and starring Ewan McGregor. Pitched by Mackenzie as a cross between Last Tango in Paris and Jean Vigo's L'Atalante, the film (which receives its world premiere in Cannes tomorrow) is being touted as the boldest and most uncompromising Scottish-made feature since Trainspotting. Some are also heralding it as McGregor's return to his roots, a strange irony given that Trocchi spent so much of his career trying to escape from his own Scottish background. The novel isn't exactly a paean to its author's homeland. Tellingly, Irvine Welsh called it "a breath of fresh air after all those horrible, sickly celebrations of Scottishness".

Whatever else, the film is bound to bolster the cult around Trocchi, the renegade novelist (and heroin addict) who fled Scotland to pursue his literary career in Paris and the US. A reckless, promiscuous wayfarer often dubbed the "Scottish Kerouac", he consorted with such figures as William Burroughs and Samuel Beckett. When he did return to Scotland in the early 1960s, to attend the Writers' Conference at the Edinburgh Festival, he provoked a huge row by having the temerity to take on the poet, Hugh MacDiarmid. Trocchi boasted that "of what is interesting in the last 20 years or so of Scottish writing, I have written it all," adding that his main preoccupations were "lesbianism and sodomy". MacDiarmid dismissed him as "vermin" and "cosmopolitan scum". Trocchi was vilified. "The prodigal son had the impertinence to take on the iconic father-figure and was excommunicated from the church of Scottish literature as a result," wrote the academic John Pringle of the rift.

McGregor plays Joe, a character all too closely based on Trocchi. He's a young drifter working on a barge alongside a dour older man, Leslie (Peter Mullan) and his wife Ella (Tilda Swinton). When the corpse of the young woman turns up, it's apparent that Joe knows more about the circumstances of her death than he lets on.

Joe is part existential outsider, part Jack-the-lad who regards sex as a way of defying the society he so dislikes. As portrayed by McGregor, in a donkey jacket, with hair swept back, he looks a little like Marlon Brando in On the Waterfront. This is certainly one of McGregor's strongest performances. He plays Joe as a brooding, curiously detached figure, who seems to be at a remove from his own life. Whether trying to seduce Ella, witnessing the murder trial that he himself has triggered, or cheating on Ella with her sister, he rarely displays more than a flicker of emotion.

What's so fascinating about the film is the way Mackenzie combines realism and sensuality. He goes out of his way to show how dour 1950s Scotland was. The colours are desaturated, as if the sun never shines. Whenever we see Ella, she's either peeling potatoes or making tea. The pubs where Leslie and Joe go to play darts are as dark and gloomy as churches. There's never enough hot water. (In one poignant scene, we see McGregor and Mullan scrubbing each other's coal-grimed backs.) Against this oppressive backdrop, a claustrophobic and erotic drama is played out.

The sex scenes in Young Adam are frank without ever seeming prurient. Joe is recklessly promiscuous. There's a desperation about his flings. In the most brutal (inadvertently comic) scene – and the one most likely to be talked up by critics looking for sensational material or for echoes of Last Tango – he empties half the contents of the kitchen cupboard, including a bowl of lukewarm custard, on a young woman (Emily Mortimer) before leaping on top of her. "There's a lot of sex," Mackenzie concedes. "I worry that people will think we're trying to court sexual controversy, but that was never my intention. The French have done quite enough of that in the last few years. It's just that Joe is the kind of character who uses sex to hide from the world."

The same could be said of Trocchi. The original novel exists in two versions. Desperate to make money, Trocchi churned out a pornographic edition for the Olympia Press in Paris. When he first started writing the script, Mackenzie attempted to read this. "I got about 20 pages into it, but then I thought, this is going to taint me. This is going to make me start hating this. There's an innate cynicism about pornography and I just didn't want to go there."

The actors felt similarly wary about Trocchi's extreme image. "I think he was probably a fucking horrible man," says McGregor. Peter Mullan admits he's exasperated by the novelist's machismo and self-indulgence. "Obviously, the character of Joe is very much based on his [Trocchi's] conception of himself. It's a young man's book. If I was 15 and I read Young Adam, it would have blown me away, but I'm 43. His view of life was pretty destructive and that didn't help him. I don't mean to denigrate Trocchi," says Mullan quickly, "It's no bad thing to be a pioneer, even if he didn't crack it himself."

For some critics, of course, any attempt to "understand" Trocchi amounts to an endorsement. The film's producer, Jeremy Thomas, is resigned to the fact that Young Adam will be attacked by the same right-wing UK critics who came after his earlier effort, Crash, when it premiered in Cannes in 1996. "I know that they're not going to feel for the film. You're looking at a different set of morals and beliefs." Thomas sighs. "I expect it like I do with [David] Cronenberg or any other director whose work has any oomph in it in a sexual way."

For years, no financiers wanted to back the project, largely because Joe was such an unsympathetic character. It was thanks to McGregor, who talked up the project onParkinson and furiously lobbied the UK Film Council to support it, that the film was eventually greenlit. "He looks older and he's playing a more mature character than he has ever played before," Mackenzie reflects. "Whether the teenyboppers will like it or not, I don't know..."

Like the author who created him, Joe isn't easy to warm to. The irony is that McGregor somehow renders the character sympathetic in spite of himself. Just as in Trainspotting, you end up rooting for Joe... whatever he does with the custard.