`Orlando' director Sally Potter's new movie is about a film-maker called Sally who falls in love with her tango teacher. She sees it as pursuing a dream, but not everyone is impressed by its autobiographical nature

Two days ago film director Sally Potter was in the clubs of Buenos Aires happily dancing the tango with her teacher Pablo Vernon. Today she's back in London defending her decision to make a film about it.

The Tango Lesson describes how a film-maker called Sally abandons a Hollywood screenplay to make a film about her love affair with the tango, and a dance teacher - called Pablo. Potter has described the film (in which she stars, with Pablo) as existing perilously "on a knife edge between reality and fiction", but knows that other kinds of knives are out in the run-up to the film's release: sharply critical ones ready to cut down to size any self-indulgence.

"I knew my choice of subject matter for this film was very risky. I dreaded being accused of making a `vanity project', and I have been, but thankfully not from all quarters." Describing the casting as "practical" (it would have taken far too long to train another actress to dance), Potter says that "to put yourself on screen on three or four hours' sleep a night, at the age that I am, in a harsh light, is not about vanity". Instead, she describes filming the tango as a long looked for opportunity to make a musical. "I love musicals. Film is an inherently musical genre, with rhythm and movement. Raging Bull was a musical if you look at it in a certain way. The question was how to make a musical for the Nineties, and I decided to make one about intimacy and relationships, because that's inevitable with the dance. It's the language of the body."

For Potter, The Tango Lesson is also about "the attraction of opposites, between Anglo-Saxon and Latin American cultures, between male and female, between the watcher and the watched." So was it strange for her to be in front of the camera, rather than safely tucked away behind the lens? "I didn't look at myself very much. I did tests before hand, to check the chemistry between Pablo and myself, but that was it. As a director it's in your interests to make the actors look as good as possible, so you'll protect them. Change a line, change a scene, a light, to make something gel. I couldn't do that for myself because I was watching the other actors. I had to accept that as a performer I was very much alone. What I tried to do was to let that nakedness come through in my performance. Partly because I hadn't any choice, partly because I thought it was all right for the part. Her level of "vulnerability and self exposure" has, she says, moved many people, although she recognises that it's this very quality that others have labelled "the hubris factor".

Despite some painful scenes of rejection, Potter shakes off any suggestions of an emotional shoot. "It was acting when it came to it. The fourteenth take, at four in the morning, of an emotion one might or might not have had a year before, was acting. It was She, it wasn't I. Quite a lot of the things in this film never happened to me or Pablo. It's fictionalised."

One real event that has translated pretty directly onto film, however, is an uncomfortable meeting between Potter and a group of studio executives. After Orlando, Potter says she received many offers from Hollywood, and even pitched some of her own ideas over the Atlantic. A fairly gentle satire, she's upset some have read it as a sanctimonious comment on the superiority of her own brand of personalised, European film-making over commercial cinema. Rather "it's about choices, about what place in yourself you're working from, love or hate, irony or sincerity".

The movie Potter pitches in The Tango Lesson was a real treatment she'd written for a film called Rage, a critique of the fashion industry, but the director decided to ditch the film in her head and follow her heart. "The Tango Lesson is about risk. About my character being able to give up who and what they were in order to pursue an irrational dream. The more I talk to people, the more I realise that everybody harbours these dreams. What's wrong with pursuing something you're passionate about? I think everybody should be more self-indulgent".

`The Tango Lesson' is on general release