Jeanette: could anyone be as good as she thinks she is?

No writer is more ambitious

than Jeanette Winterson, or

more self-aggrandising. And yet,

Angela Lambert found herself charmed by her vulnerability.

Jeanette Winterson, asked in 1995 to select her favourite living writer, said: "No one working in the English language now comes close to my exuberance, my passion and fidelity to words." These may be the most famous - certainly they are the most notorious - words she has ever uttered and they did her enormous damage. The English prefer their writers modest.

Gut Symmetries,Winterson's sixth and latest novel, was published in 1997 to unfavourable reviews. But the novel sold well enough, if not as well as the scintillating early ones. Her fans mostly remain loyal. But for how much longer? Whatever happened to Jeanette Winterson?

In the mid-1980s, Winterson's early novels catapulted her to acclaim and commercial success. The first was Oranges are not the Only Fruit (1985). In 1987 came The Passion. With her open avowal of lesbianism, indifference to the literary establishment and stunning inventiveness, she captivated her generation; not only in Britain but also in the rest of Europe and ultimately in the US. Most critics would agree that she has not written a book worthy of her gifts since Written on the Body in 1992. It may be significant that this novel chronicles the end of an unhappy love affair and the rapturous beginning of a new one. It is dedicated, like everything she has written since then, "For Peggy Reynolds with love." As is common knowledge, she had a turbulent liaison with her agent, Pat Kavanagh, in the mid-Eighties which ended in 1989 when the relationship with Peggy Reynolds began. The two women have lived together ever since. Reynolds is a feminist academic and broadcaster, now working on a book about Sappho.

Despite the critics, Winterson's readers remain numerous. Her sales may be dwindling, but they are still high enough to keep most "literary" authors happy. At a rough estimate she probably earns pounds 200,000-pounds 250,000 a year. This would put her among the top 50 English writers for earning power. Winterson earns enough to pay a number of dedicated women to cater for her domestic and administrative needs, freeing her to concentrate on "The Work" (as she refers to her writing).

We meet at the house in Spitalfields which she has recently bought and renovated. The door is opened by a young black woman who introduces herself as Vicky. (This is Vicky Lickorish, the actress, one of a quartet of loyal friends who have supported Winterson for more than a decade.)

Vicky leads the way up a wooden flight of stairs to the first floor. There, perfectly placed, perfectly lit, gazing out of the window in proud isolation, stands Jeanette Winterson. The pose is so blatantly Napoleonic that I expect her to swing round with a self-deprecating laugh, but self- deprecation is not in her repertoire. Eventually she turns. "Pleased to meet you," she says, and leads the way into a small, austerely furnished room.

In person, Winterson is courteous and soft-spoken. She is small, with a wiry body, fierce tomboyish looks and short dark hair through which she constantly runs her fingers. Several years ago she posed naked for the jacket of a foreign edition of The Passion. At 38, she still could. She isn't in the least pretty but her face is compelling and her black eyes snap with intensity.

She appears nervous, as a friend of hers told me to expect: "She's petrified; she gets a fear of being given a hard time." So, for that matter, am I. Several weeks before this meeting I had an anxiety dream about her. I have interviewed Arthur Miller and Iris Murdoch without suffering anxiety dreams, which shows how effectively Winterson has imposed her formidable personality on my journalistic psyche.

Winterson was born in 1959 to unknown biological parents about whom she claims to feel no curiosity. Adopted at the age of six weeks by John and Connie Winterson, she was brought up in their small terraced house at 200 Water Street, Accrington, in Lancashire. Her father worked in a television factory; her mother was a housewife. They were what sociologists call "respectable working class". Winterson makes much of the poverty in which she grew up.

Her adopted parents were Elim Pentecostalists: a fundamentalist sect which believes that every word in the Bible is literally true. Winterson claims to have grown up in a cultural desert: no books in her home, no paintings, no records of classical music. However, for a contemporary author she did acquire one rare asset - a thorough knowledge of the Bible. In a striking phrase, she said: "God was so tattooed on to me that I can't but believe in him." She had a passion for telling stories and was surrounded by people for whom the oral tradition remained strong.

By 1971, at the age of 12, she was already preaching and saving souls. Her mother wanted her to be a missionary. The messianic streak has had an extraordinary effect on her as a person and a writer. (More than one person told me: "Winterson used literally to believe she was God.")

The reverence she inspired in her fellow Pentecostalists did not last long. In 1975, aged 16, she was discovered in bed with a lesbian lover - legend has it, a fish-filleter - and publicly denounced by the Pentecostalists. Undeterred, she left home and took her A-levels at a local technical college, supporting herself by doing various odd jobs, as an undertaker's assistant, in an ice-cream parlour, and a domestic in a mental hospital.

In 1978 she sat the entrance exam to St Catherine's, Oxford. Having failed to pass at the first interview, she claims to have told the admissions tutor: "You must let me in. It's crucial." She was so insistent that they relented.

She insists that it is exceptional for a writer to emerge from a background such as hers. When I instance the many other writers who have done it - Dennis Potter, for example - she evades the comparison. "To be working class means physical poverty, but it also means to be in a cultural ethos which is undernourished so that there is nothing outside the factory and the pub," she says. This belief that coming from a proletarian background is a virtually insurmountable handicap, seems historically naive, not to mention self-serving. Working-class authors from DH Lawrence onwards have always been able to get into print if they had sufficient talent. This is true of women too: take Shelagh Delaney, Pat Barker or Sue Townsend.

Winterson herself had been published by the time she was 26. Yet in the course of our meeting she only became confrontational once when I suggested that middle-class children could also be at a disadvantage; could also come from Philistine or culturally impoverished homes. Her voice rose and sharpened; her Northern accent, usually almost undetectable, became more emphatic.

"I really don't accept this. One of the things that annoys me enormously is when middle-class people think of themselves as underprivileged, when they have no idea what it means to run out of money on Wednesday and not get paid till Friday and not have a bank account and not have a telephone and not have a car and not know anybody who's got any of these things - these are the things that really separate people out. It's different in every respect ... I don't know anybody - anybody - from my background who has been able or has really wanted to cross the bridge into my kind of life."

After three years at St Catherine's she took an unflashy degree in English. She made her way to London, and as a raffish young graduate undertook a series of odd jobs which included working at the Roundhouse theatre, three weeks as a stockbroker, bits and pieces for a publishing firm called Brilliance Books (now defunct) and also for the Pandora Press which eventually published her first book; and prostitution. Prostitution? When I ask about this rumour, which surfaced in an interview, Winterson does not repudiate the story, only the use of the word prostitution.

"I took exception to that. It was not a word I had used. It can only be understood by overlaying it with a heterosexual template. A prostitute is somebody who solicits for work professionally and is paid for it and I tried to explain that this wasn't the case. No money ever changed hands. What I did was not prostitution." But she was paid - famously - in Le Creuset saucepans.

Winterson has been accused in the past of manipulating publicity and this story seems almost too good to be true. She must have known the headline writers would have a field day with Le Creuset and that the resulting notoriety and laughter would boost the sales of her latest book.

It was a story from a time when she had a lot of jobs; many lovers; not much money. Like other young writers she needed a mentor. In the late 1980s, she had an exceptionally lucky break. Thanks to Pat Kavanagh she met the crime novelist Ruth Rendell and her husband Don. Winterson's next four books were written in their garden shed: she calls it a "hovel".

"I was living in one room in Kentish Town and above me lived a concert pianist with a grand piano. I realised I needed some space.

"I've got my own hovel now, at the bottom of my own fields, where I alternate periods of intense idleness and frenetic activity. I know when the day's work is finished because I lose a kind of intensity. I feel it beginning to drain off so I stop because otherwise I start gibbering. When I've finished I show it to Peggy. I trust her because she's analytical, and she loves me and understands the way I think. But when I work, there's nobody between me and the words. It's like a lovers' relationship - tender, intimate, vulnerable. I never know if I'll be able to write another book. Each one is a miracle and a surprise."

For the time being Winterson doesn't have a book underway. She has a collection of short stories due in the summer and she is doing a script of The Passion for Miramax, and enjoying it. "I like the glittery excitement and the collaborative nature of the film world. I'm curious about Hollywood. I've banged out a very good contract though I probably haven't thought of everything. If they do make a terrific film of The Passion it will bring many more people to the book." Which is what really matters to her.

I read or re-read all her books in the space of a few weeks and found myself much more indulgent to her shortcomings after meeting her. Contrary to her defiant public stance, her vulnerability in private is touching and her dedication to writing utterly sincere. It would be premature to say she has shot her bolt. But for the time being Winterson seems to have lost her way - perhaps through striving too hard for new effects. It is a tall order to re-invent the novel every time.

This is an edited extract from an article in the current issue of 'Prospect' magazine, available at most big newsagents or call 0171-255 1287