It's not what you expect from a well-brought-up Mormon: a vicious tale of deceit and misogyny in the world of American corporate finance. Liese Spencer takes on writer-director Neil LaBute.

Writer-director Neil LaBute is a chubby, cuddly bear of a man, his handsome actor friend Aaron Eckhart all clean-cut charm. Both Mormons, they met at a church school: Brigham Young University. On a course called Ethics in Film. Not exactly the kind of nice young men you'd expect to produce this year's most brutally misogynistic movie.

In The Company of Men, 34-year-old LaBute's directorial debut, is set in the competitive world of corporate finance. It focuses on a pair of angry young marketing men. Chad is a smooth-talking shark, Howard a doughy sap, but they're united by job insecurity and a hatred of women. Dumped by their girlfriends, they decide to take revenge on the opposite sex by simultaneously seducing and dumping Christine, a sweetly vulnerable, deaf secretary. Just because they can.

"I started with Chad's line, `Let's hurt somebody,'" remembers LaBute, "and developed the script from there". Plotting his story around the standard "abuser", "victim" and "ordinary guy", LaBute decided to "tip this classic love triangle on its side to examine issues of control, manipulation and betrayal". Dispassionately shot, the resulting immorality tale seethes with rage and malevolent humour.

"My model was Restoration comedy," says LaBute. "I saw a parallel between the 1690s and the 1990s, the tendency not to wound with fists and swords but with words." An archetypal rake, Chad's shirt-sleeved sadist is more than a match for Valmont. Priming Howard for their frat boy prank he tells him, "Women - nice ones or the most frigid of the race; it doesn't matter in the end - inside, they're all the same. Meat and gristle and hatred." When Christine, who has fallen in love with him, discovers his betrayal and confronts him, he coolly inquires, "So how does it feel?"

Already dubbed "a psychological snuff movie" by one American critic, LaBute's redefinition of white-collar crime has aroused reactions the writer-director describes as "visceral". For him, Howard, "who has a moral code but chooses to deny it", is the more despicable character, the "good German" to Chad's "uber Nazi". But it's Eckhart's portrayal of suave sociopath Chad that has provoked most audience abuse. "Early on people were shouting at me at screenings," the actor remembers. "There were a lot of `bastards' and `pricks' and people saying `I hate you.' One woman tried to hit me."

Such violent reactions may be new for Eckhart, but to LaBute they're all too familiar. As a graduate playwright at BYU his raw treatment of relationships caused consternation among the administration, while a gay- bashing diatribe by a character in his Aids play Filthy Talk For Troubled Times was met by a call from someone in the audience to "kill the playwright". When LaBute showed In the Company of Men to a group from Sony Pictures one executive told him that it "made him sick".

It was while working for a large computer software company after leaving university that LaBute first decided to set a screenplay in the modern American workplace. "I got to visit a number of companies," he explains, "and they were all the same. Lots of men walled off into little cubicles speaking a jargon that didn't really mean anything. You couldn't really work out what it was they did, but there was always this business ethic - I'm not sure ethic is the right word - a code, by which they operated. They're paid to have no conscience, to tear each other up for the greater good of the company."

Packing a nasty verbal punch, LaBute's portrait of aggressive alienation has already been compared to Mamet's Glengarry Glen Ross, and it's easy to see why. Both films anatomise modern masculinity through language, depicting the office as a battlefield, fought over by salesmen so hungry for success they're practically cannibals. During one particularly degrading scene in LaBute's movie, an intern is made to drop his trousers to show Chad whether he has "the balls" for the job. "That's what this business is all about," Chad tells him, "who's sporting the nastiest sac of venom, and who's willing to use it".

As Chad's advice to his young colleague makes clear, In the Company of Men is less a bellicose dispatch from the sex war than a chilling study of the way the predatory corporate mind-set can colonise all social relationships. Man or woman, at home or work, it's dog eat dog. In a final, vicious twist to LaBute's schematised story, it becomes clear that it's not Christine Chad really wants to crush, but Howard.

When Eckhart's financier brother witnessed the intern scene, he says, "his knee-jerk reaction was, `That's it. That's investment banking.' I trust him because he's worked in that environment, for a firm where all the men had to play basketball on a Saturday and the wives had to go on the company picnic. It's like the mafia."

"A guy from Entertainment Weekly in the States told us a really scary story about their sales staff," chips in LaBute. "He said they had a lot of stars passing through their office, but the only time the marketing people got excited was when Alec Baldwin came down. They all got out their pictures from Glengarry Glen Ross to be autographed. That was the guy they identified with. The one they wanted to be. The bastard `closer' with the brass balls. It makes you worry there's someone, somewhere who's looked at In the Company of Men and thought, `you know, that idea isn't half bad.'"

In fact, after one interview, LaBute says, the journalist took him aside to congratulate him. "He said, `I didn't like what Chad did to that girl but I admire the hell out of that guy. People that I know in the business world really respect Chad."

For Eckhart it was "fun" to play the cad; was it similarly exhilarating for LaBute to script him such savagely un-PC lines? "Were they unpleasant?" he asks, feigning innocence. I remind him of the meat and gristle. "No, there's no great thrill in it. Oops, that makes me sound like Chad doesn't it? `I just had to do it because I could.' Maybe I should say it was great therapy, but it really wasn't. Once you've created a character you're either true to them or true to audience expectations."

If it's gruelling to be in the company of Chad, then that's exactly what LaBute intended. "Sure, it's a bit relentless. People enjoy watching an evil character on screen, but always with the hope that they get what's coming to them. Since childhood we've been told good triumphs over evil, so when that doesn't happen audiences have a gut reaction. But if you can step back from that you can see it makes sense. People like Chad don't always get punished."

So what happened to those Film Ethics? "I think it's a really moral film in a way. It's got an amoral sensibility but in the end it's quite a harsh look at the way men operate," he argues. "Howard tries to say he's sorry to Christine, but he doesn't get the chance. As far as I'm concerned, he doesn't deserve it. In that way it's a very Old Testament film. You sin, you pay. We'll get to redemption later. If we'd just stayed with these men a bit longer we might have seen that happen, but that's not what interests me. As a writer I raise questions, not answer them. I think of the film as an exercise in anti-catharsis."

LaBute has said that while men try to consign the film to science fiction, "women are relatively sure it's a documentary", so where does he stand? Does he really believe that there are monsters such as Chad out there? "You know, if there are Chads out there, and they're that good, how would I know? Like everyone else I've been deceived into thinking they're nice people. That's how they exist, because they never get caught."

And with that LaBute hands me a coffee. "It's all just a ploy to make you like me," he grins. "It's all calculated."

`In The Company of Men' opens next week.