Brokeback Mountain, Hollywood’s first gay cowboy film, has not enthralled that bastion of rectitude, the Culture and Family Institute of Concerned Women for America. “Ang Lee is off his rocker if he thinks he can have the same commercial success with two cowboys instead of a cowboy and a cowgirl,” said its spokesman, Robert Knight, who lamented the “perversion of the straight-shooter”.

The critics and other filmgoers could not disagree more. The Taiwanese-American director’s western epic has been praised as lyrical, visually stunning and achingly sad. It has received seven nominations for the Golden Globe Awards — an auspicious sign of its Oscar prospects — and last month was voted film of 2005 by Los Angeles and New York film critics.

This ringing acclamation for yet another daring movie by Lee confirms the 51-year-old director’s talent and astonishing versatility. He made the definitive version of Jane Austen’s Sense and Sensibility, switched genre to produce and direct The Ice Storm, a ferocious assault on loveless but permissive 1970s America, then triumphed with the Asian martial arts story Crouching Tiger, Hidden Dragon and the cartoon classic Hulk, before turning to a love story between two lonely drovers.

It is as if he is taking on Stanley Kubrick’s quest for perfection in different movie genres or the mantle of Monkey, the irrepressible character created by the 16th-century Chinese writer Wu Ch’eng-en, which can clone itself into innumerable personas to bewilder its adversaries. Lee’s explanation is more prosaic: “I do not want to be limited in a certain genre. That’s not a career I want to go through. I have to learn step by step.”

Lee is a small, wry man with a cheeky face and a beatific smile who is apt to giggle and deliver convoluted sentences that are a reminder of his comparatively recent mastery of English. He hardly spoke the language while he was making Sense and Sensibility in 1994, despite his years of living in America. He credits Emma Thompson, who adapted Austen’s novel and starred in the film as Elinor Dashwood, with helping him over the language barrier.

“I learnt a tremendous amount from Emma,” he said. “I was directing Jane Austen with the finest English actors. I had pidgin English. But I didn’t let on I was scared.”

He first read the tale of two lovelorn farm hands four years ago. “I got choked up,” he said last week. “It was a wonderful piece, in beautiful prose.”

Brokeback Mountain was originally published in the New Yorker magazine in 1997 as a short story by Annie Proulx, who wrote the novel that became the film The Shipping News. It is set in the hills of Wyoming in 1963 and follows the converging trails of two loners, played by Jake Gyllenhaal and Heath Ledger, who tend sheep and barely exchange a word for weeks on end. One freezing night they share a tent and their moment of intimacy becomes a melodrama of parting and subsequent reunion as married men with families.

As far as Lee is concerned the film, more a haunting portrait of rural life than a western, is about love and loss. “Gay or not, it is a vehicle for universal human feelings,” he said. The problems some people will have with it, he has said, are ideological, not moral. “It always confuses me, what Americans call moral issues.”

He envisaged the film as a small, art-house movie — the gay label frightened off backers and, to save money, he was forced to shoot many of the Wyoming scenes in Calgary, Canada — so the talk of Oscars has caught him unawares.

It is his second gay film. His 1993 movie The Wedding Banquet, which he wrote and directed, was his breakthrough, a charming comic farce about a gay Taiwanese New Yorker marrying a Chinese girl to appease his blissfully ignorant parents. The crew assumed that Lee was homosexual until his wife, Jane, a microbiologist, and their sons Haan and Mason visited the set. “Jaws were dropping,” he recalled.

It has not been roses all the way for Lee. Ride with the Devil (1999), his spectacular American civil war movie about lawless American mercenaries, received a critical mauling. And reviewers saw Hulk as less than Shakespearian.

Like the central character in Hulk, Lee is something of a split personality. His meticulous attention to detail and perfectionism can transform him into an ogre who demands dozens of takes. Eric Bana, the Australian actor who played the Hulk’s human persona, Dr Bruce Banner, said: “I would describe him as a sledgehammer wrapped in cotton wool. He’s a very tough man, very tough.”