And both suggest comparisons with Ken Loach, who preceded them in the field of committed, improvisational drama. Blair and Loach are now partners in Parallax Films, and Loach has recently made Carla's Song, an impassioned polemic in which Robert Carlyle plays a Glasgow bus driver whose political consciousness is raised when he falls in love with a Nicaraguan woman. You may feel that you know what to expect, then, on learning that Les Blair's latest film, Jump the Gun (15; opens on 22 Aug) is set in Johannesburg and takes as its starting-point the encounters of a white man (who is a political innocent) with an Afrikaner prostitute and a young black woman: another story about love raising awareness. It would be wrong to make too many assumptions, however. For a start, the film has been well-received in South Africa itself, so Blair must have got something right, and what is striking about his work is not only that it confirms his liking for people but that it exhibits a sense of humour which has so far managed to elude Ken Loach.
None the less he is treading on what could be dangerous ground. When we met a few weeks ago I asked if he'd known South Africa well before starting the film. "I'd never been to the country - in fact I'd conscientiously stayed away," he said. (Of course, silly question ...) But, he added, as he'd made films in this way before and always gone into them "only having a notion of the territory rather than a story", the whole enterprise felt "more exciting than risky". He spent about a month absorbing the feel of Johannesburg, then started auditioning actors. For the two main white roles he chose Lionel Newton and Michele Burgers. Surprisingly, perhaps, he doesn't like working with amateurs: Newton is an experienced stage actor and Burgers works a lot on television. The black actors had a different background, mostly in community theatre projects, particularly the Market Theatre, and because of this "they adapted to my methods rather effectively".
On arrival he had no idea what the film was going to be about; all he knew was that he wanted to show working-class Johannesburg - "the scruff element if you like". When he had chosen his leading actors, he asked them to hunt through "the address books" of their minds for a possible character, which was then painstakingly refined in one-to-one sessions with Blair before any member of the cast met the others. When the actors were finally introduced, the rehearsing period began in earnest with improvisation and analysis. Towards the end, Blair wrote the story of the film which became the script. "Everything you see in the film is the essence of an improvisation," he says.
The work is demanding for the actors. When I asked how Michele Burgers researched her part as a white prostitute, Blair replied: "Carefully." In fact he put her in touch with the madam of a brothel who allowed her to sit in with the other girls (but to turn down clients). The point of the character, Blair insists, is "not just to add spice" but to illustrate a reality of the new South Africa. "One of the prices you pay for freedom is a burgeoning sex industry," he says. Lionel Newton as Clint, a white electrician back from a spell on the oil rigs, falls in love with her, not realising how she pays the rent. "A number of people have said naive," Blair says when I try to sum up the character, but he doesn't entirely agree. Clint is from a white suburb on the edge of the city, "with no cultural centre - the sort of place where you can buy biltong [sun-dried meat] pizza..." Like everyone in the film he is seen as a victim, in his case of a system that has left him with "a very enclosed life experience".
It turned out to be harder, in one way, working with the black actors, Baby Cele, Rapulana Seiphemo and Thulani Nyembe. Blair soon realised that they were not happy improvising in English, their second language, so he said to do whatever seemed natural. The result is a film that uses a patchwork of tongues with subtitled sections when the characters are speaking in Xhosa, Zulu and so on. This reflects South African English, which borrows from Afrikaans and Portuguese as well as the African languages.
Blair explains all of this with enthusiasm, though he has probably been through it many times before. There is no doubt that he cares about what he does. He talks slowly with a hint of deadpan humour. When I mention the budget and ask if he feels optimistic about the future of British cinema, he says, "I'm told I should be", with the tone of someone who doesn't like to do as he's told. At times one senses almost a contradiction between his open-ended method and his determination that the final product should convey the meaning he intends. Just as the sex in the film illustrates a reality of post-apartheid South Africa, he insists that "the humour is not just there to amuse, it's something that I see in Johannesburg. It's almost like a ghetto humour - a way of dealing with the violence and all the difficulties in the transitional period". Nothing is gratuitous if there's a lesson to learn.
As I said, it is not hard to see where Blair is coming from. The open- ended approach is neither anarchic nor, in the end, undirected. He has almost too many answers to the question of why he prefers improvisation: the end product not the method is the issue; the influence of other directors, like Milos Forman and Ermanno Olmi; "the quality of performance" that he obtains and "the feel"; and the fact that he likes "films that are character-led and have a non-aggressive style".
The last adjective is an odd one. What is "aggressive" about films made in a traditional way from a script with actors speaking their lines? "I find the story and the push towards short scenes with short chunks of dialogue unengaging," he says. "I suppose it's aggressive in the sense of being hyper-commercial and competitive: in the end it's not human."
The audience has to adapt its mood to the pace of Blair's film and its expectations to the narrative style: there is no neat development or conclusion. But the "non-aggression" does not mean he has no designs on us, that he is offering a mere glimpse of Jo'burg low life, a slice of biltong pizza. Jump the Gun is more subtle than Carla's Song but, underneath, just as didactic and committed - to what is, finally, a positive view of the rainbow nation's future. "One feeling I had right from the beginning was that I wanted to make a film that was going to be optimistic," he says. "It doesn't say here's the answer, but it ends on a note that says here's the potential for an answer."
Where Les Blair comes from, you do believe that people of different backgrounds and cultures can one day learn to get along.