A writer who regards her political stance as a white South African very seriously, Nadine Gordimer tells Marianne Brace she has never regarded herself to be a propagandist.

Nadine Gordimer is aghast with indignation. The other night, she tells the hotel receptionist, she took a London cab and the driver claimed he didn't know the whereabouts of Regent Street. "Why on earth was he doing that job?" Gordimer wants to know. The humour of the situation escapes her.

But then Gordimer - Booker and Nobel Prize-winner, friend of the Mandelas, ANC member, spokesperson for the United Nations Development Project to eradicate poverty - isn't someone whose books you turn to for an easy laugh. For almost 50 years Gordimer has chronicled the political shifts in her native South Africa with an earnest passion. She has written 12 novels and some 200 short stories. In her new book The House Gun she keeps the same fierce grip on her material.

Gordimer at 74 is small, brisk and birdlike. No, she won't be photographed while talking. Yes, of course I must use a tape-recorder. It's not so much that she's imperious, but that she's been interviewed so many times she knows it's best to be firm.

Although Gordimer claims not to write herself into her work, her women characters are often forcible, intelligent, admirable but not terribly likeable. And she is severe on her protagonists. Gordimer "can't stand" Mehring, the businessman farmer in her award-winning The Conservationist. "He's such an awful man." She dismisses Claudia and Harald Lindgard in The House Gun as "typical liberals - they always say they have no racial prejudice but didn't protest, never did anything to further liberation."

In Gordimer's works her characters are mapped against the political dynamic. She's perceptive about relationships but always within the context of the larger picture. At a time when the focus in South Africa is on truth and reconciliation, it's no coincidence that Gordimer puts both under scrutiny in The House Gun. The Lindgards must accept the truth about their son and become reconciled to it. For Claudia and Harald's adult son has killed a man in a crime of passion.

"I became fascinated by the idea of how people who have certain values would deal with something that was quite out of context of their lives. They couldn't imagine their son would solve an emotional problem by murder. What is the responsibility they have towards their child who does something incomprehensible to them?"

In keeping with earlier works, the central relationships are analogous with what's happening in the country as a whole. "Blacks always had to come to whites for help with dealing with authority. For most of my life a black adult had to have a pass if he wanted to be in town after a certain hour. Any white person, even a child, could write out a pass for an adult black man. So there was this dependency, enforced by law."

The Lindgards find the situation reversed. They are dependent for their son's life on a black lawyer who must speak for them.

Gordimer's own political consciousness was raised through reading books like Upton Sinclair's The Jungle. "My parents didn't want anything to do with politics. I had to discover my society and its incredible distortions for myself."

As a girl, she wrote a story about the black miners she passed on her walk to school across the Veld.

"They seemed to me to be extremely exotic," says Gordimer. "Many of them came from what was known as Basutoland in their terracotta tribal outfits and dreadlocks, which were covered in clay. They would come into the shops and I saw the difference in the way they and my mother and I were treated. This was one of the first things I began to wonder about."

Would it have been possible for Gordimer to live through apartheid and not have written novels so underpinned by politics? "How could this be unless I was writing fantasy?" she asks incredulously. "Would you ask this of an Irish writer, a writer from Afghanistan? I don't understand why this is a question for a South African?" It's a question for any writer. Jane Austen felt no need to refer to hostilities with Napoleon.

But, Gordimer argues, "It's impossible not to - for anybody who has any honesty or any sense of where they are living. To be a writer is to be observant of what is happening to the people around you."

The novelist was born in a gold-mining town on the outskirts of Johannesburg. Her father emigrated from Latvia, alone, aged 13. Her mother's family were Jewish Londoners. Her maternal grandmother Phoebe curled feathers ("they needed to be cleaned and stroked") for Queen Victoria. "When my grandmother and her sister came back from work they would huddle together through the streets because they were frightened of Jack the Ripper. I have an affection for my feather-curling ancestor," says Gordimer with a smile.

Gordimer's maternal grandfather went to South Africa to prospect for diamonds in Kimberley, taking Phoebe with him. But one night Phoebe opened the door to find a Chinese labourer, with his throat cut. "He staggered in and died under the kitchen table," says Gordimer. Phoebe fled back to London and didn't return to South Africa for six years.

New South Africa is still as violent and, says Gordimer, "awash with guns". She believes there's a general acceptance of violence in cities all over the world, even, she says, "here in your civilised democracy that you've had for so many years".

In The House Gun Duncan shoots his former lover using a gun which is left lying around - insurance against "being gagged, raped, knifed". But protection is not just the obsession of middle-class whites. "That's another thing you people who live abroad don't understand," says Gordimer. "If you go into the black townships in Soweto, there are razor wire fences, dogs, tremendous security. Everybody is suffering from the prevalence of violence. We're all under threat."

As a writer, Gordimer has felt no personal danger. ("There were other things I was doing that were dangerous," she says enigmatically.) "One has to be fair. The apartheid regime didn't put writers into mental hospitals like the Soviets, but they feared writers. I had three books banned, I was watched, my telephone was tapped, but nobody came to my house and took away my typewriter, which happened to black comrades."

What comes across in Gordimer's work is her love for South Africa and its people. "In Burger's Daughter I wrote that, despite everything terrible that was happening, it was amazing to live in a country where there were still heroes. There have been miracles in our country."

Gordimer has "never allowed myself to become a propagandist - it might have been very useful to my cause if I had been. I've always kept my integrity to write the truth as I see it and not to promote one side. I'm also a citizen and a white one and therefore bear a special ancestral responsibility for what has been done to black people. I had to find ways to fulfil that by identifying myself with the liberation struggle. But my writing came first and it requires a kind of standing back."

For Gordimer, the written word is a way of dealing with life's complexities. "The arts are a way of ordering that extraordinary chaos, of making something of it, of giving it meaning."

`The House Gun' is published today by Bloomsbury, pounds 15.99