If you were to ask most people what impression they have of Doris Lessing, our only serious contender for the Nobel prize for literature, they would probably tell you she is the firebrand communist author of The Golden Notebook, one of the great feminist novels of our times.

Her novels — more than 50 of them — repeatedly attacked the behaviour of white people towards black, challenged sexual stereotypes and, at the end of The Golden Notebook, seemed to suggest that joining the Labour party was the solution to public and private woes. Yet like numerous other former luminaries of the left she is now a Telegraph-reading thorn in the side of new Labour.

“We do not have a government that trusts the people, the vox pop. This is the most philistine government we’ve ever had,” she says. Having attacked the prime minister at the Edinburgh Book Festival this year as a “fantasist”, “a child of the Sixties who believes in magic” and “probably not very bright”, she longs to get rid of the current Labour government.

She was “appalled” to see photographs of Gordon Brown kissing his baby on the front cover of serious newspapers last month, she says. “I’d even consider voting Tory, though I probably won’t. We desperately need a strong opposition.”

It isn’t only Blair who has come in for withering criticism. A recent novel, The Sweetest Dream, pours contempt on a crypto-communist newspaper that is obviously The Guardian, the bible of the left. In previous interviews she has denied being a feminist and expressed a compassion for men that has been considered as shocking a recantation of beliefs as Fay Weldon’s.

True, she gave up her “neurotic decision” to join the Communist party back in the 1950s, before many other intellectuals tumbled to the evils of Stalinism. She has since described communists as “murderers with a clear conscience”. Fiercely intelligent, wholly self-educated and an indisputably great, if uneven, writer, she has given the impression of being bolshy in every sense of the word.

Yet she could not be more different. Her sun-filled upstairs room at her West Hampstead home could be that of any bohemian with its African carvings, its piles of books, its low damask sofas and vases of multicoloured flowers. There are birthday cards featuring the madonna and child, wooden masks, a wonderful old stove and a messy desk. On the floor are neatly folded copies of The Daily Telegraph and The Independent.

Yet the novels, and particularly The Grandmothers, her latest collection of short stories, do not by any means suggest this neat, pretty 84-year-old grandmother of letters is going gentle into that good night. Fierce, disturbing, gripping and unexpectedly funny, they display her uncanny prescience by writing about topics that have only recently come into debate: in the case of the first story, the sexual passion that can exist between beautiful young boys and middle-aged women.

“Astonishing, isn’t it?” says Lessing. “There’s Germaine Greer with her book The Boy, and Zoë Heller with her novel (Notes on a Scandal) — which I thought rather good — and I write this.

“I was told about the grandmothers by a young man who was a friend of the two boys. He was sick with envy at their luck at sleeping with each other’s mother. He described it as 10 years of perfect bliss, but this old sceptic doesn’t believe in that. I wrote what I thought might happen instead.”

Lessing is our greatest laureate of love — mystified by it, by the reason why two people can be instantly attracted to each other (“Have you heard the theory that we have hidden genes that match?”) and has both suffered and described its pangs throughout an immensely varied existence.

“I can’t find a pattern to the people I’ve been in love with,” she says in frustration, adding that the capacity to fall in love does not diminish with age. The subject was originally addressed in Love, Again (1996), perhaps her finest novel, and is returned to in The Grandmothers. “The whole thing is a mystery. One doesn’t now act on it, but it does go on happening. You see someone and think, ‘Yes, it’s still there’.”

Her two volumes of autobiography, Under My Skin and Walking in the Shade, describe a childhood in the former Rhodesia, where she left convent school at 13 but read omnivorously. Married at 19, as was expected of her generation, she had a son and daughter by her farmer husband, Frank Wisdom, before leaving them for Gottfried Lessing, a communist.