A RISKY business, capturing the essence of a seven-year-old on canvas – especially when you then have to show the painting to the child’s mother. Rita Angus, a New Zealand artist, managed it when she painted Fay Weldon in 1938 – really dipped her paintbrush in the murky stuff of her sitter’s ‘inner soul’. Fay’s mother Margaret, a novelist who was living in New Zealand at the time, hated it; thought that with its hard edges and simple colouring it looked like a caricature. When she returned to London with her two young daughters – following a messy divorce in which both parties admitted to infidelity – she tried to leave the painting behind.

A friend ran to the dock with it just as the gangway was rising, shouting, ‘You left this!’ Margaret considered throwing the painting in the sea but asked the friend to return it to the artist instead. It now hangs in the National Gallery of New Zealand.

In the painting Fay sits beside Jane, her older (by two years) sister. Both are wearing gingham dresses with white collars and ribbons in their hair. When I meet Fay Weldon – now 71, married for the third time, mother of four sons, author of 24 novels, most notably The Life and Loves of a She-Devil (1983) – at her home in Hampstead, she is wearing Nike pumps, black trousers and a black top. But I recognise instantly the girl in the painting. It wasn’t a caricature, after all. She still has the same icy-blue saucer eyes, the same moon face, the same high, pouchy cheekbones, the same bob of pale blonde hair. Her skin is still smooth, too – or smoothed, thanks to the tucks and nips she blithely admitted to having a few years ago. Even her hunched shoulders and no-neck posture are the same. Her expression, now as then, is one of mischief masquerading as innocence.

She takes a sip of coffee from a mug with himself written on it – her hand shaking slightly – and tells me why she has reproduced the Rita Angus painting on the dust-jacket of her autobiography Auto Da Fay, which is published this week. The book is partly about what she calls the ‘survival unit of three’: her mother, her sister and herself. ‘Writing about Jane helped me come to terms with her death [from cancer at the age of 39 in 1969]. At the time I felt total helplessness in the face of it. I had to be elliptical, though. Her children don’t know the extent of her illness. You can have too much truth.’ You can see why she might think that. The truth or facts of her autobiography can seem rather too much. Among other things she reveals that, as a young woman, she flirted with prostitution and worked as a hostess in a Soho clip joint. She thought herself plain and dull, she writes, or at least that is how her mother made her feel – but she soon learnt that it wasn’t beauty men were after, but availability. ‘Sit on a bar stool in a skimpy dress and look like you charge for your favours and perfection of leg doesn’t matter.’

One could be forgiven for wondering if these episodes have been included simply because she thought they might help sell the book, even if she does feel they represent ‘too much truth’. After all, she first found success not as a novelist but as the advertising copywriter who coined the phrase ‘Go to work on an egg’. She knows how to sell a product, in other words. This commercial sense was demonstrated admirably by the press coverage she generated for the launch of The Bulgari Connection last year. It was, she calmly announced, a product placement novel sponsored by the Italian jewellery designer Bulgari. There were howls of indignation from the literary world, who accused her of selling out and compromising her integrity. She just shrugged and said, ‘Have I betrayed the sacred name of literature? Well, what the heck?’ And when another book, Big Women, about a feminist publishing house in the 1970s, was published four years ago, she caused a storm by making the rather non-feminist comment that rape is not the worst thing that can happen to a woman. ‘No,’ she says now in a soft, breathy voice. ‘These things stir themselves up, it’s not me. And I don’t think they help with sales. If you were more mysterious and difficult as an author people would feel they had to read your books.’

Did she find it therapeutic to write about her youthful follies, then? ‘Cathartic maybe, which I do not believe is therapeutic. Things are not made better if you face them. They are just reactivated. I’m all for denial. It’s a tried and tested survival mechanism.’ She examines her nails. ‘And yet if things happened in your life, you should put them in your autobiography – even if life is less believable than art. When you make things up in a novel people recognise themselves and try to sue you for using their lives. They assume everything they do is unique. Yet we all have much in common.’

I can’t believe that many people would have had marriages in common with hers. ‘I suppose my marriages were unusual,’ she says with a gentle laugh. She is now married to Nick Fox, a jazz musician and poet 15 years younger than her, who has popped his head – bushy eyebrows, clipped beard, a cigarette between his lips – around the door to say a friendly hello. They married days after she divorced Ron Weldon, her second husband, in 1994. Ron, a jazz musician and artist, had been in psychoanalysis for ten years before he met Fay and soon persuaded her to take it up as well. ‘Both Ron and I went to see our analysts twice a week so really there was no need to speak to each other,’ she recalls drily. The marriage came to a sudden end after 30 years when, Fay claims, Ron switched to an astrological therapist who told him that the couple had incompatible star signs. Eerily, on the day their divorce was finalised Ron died of a heart attack.

But her marriage to Ron was straightforward compared to her marriage to Ronald. In 1956 she married Ronald Bateman, a headmaster at a technical college in west London who was 25 years older than her. She was a bohemian single mother not long out of university (St Andrews, where she read economics and psychology) and needed a roof over her head. ‘Poor Ronald Bateman,’ she writes in Auto Da Fay, ‘[I] was a heartless, practical monster.’

‘But actually it wasn’t so unusual,’ she tells me. ‘Marrying for convenience happened a lot. Most girls who got pregnant had the baby adopted or they had a shotgun wedding. Or the girl’s mother pretended to be the mother, so the child grew up thinking her mother was her sister. Extraordinary the lengths people went to to be respectable. When I wrote about that episode I did have a reaction. I was filled with self-pity and did think, “Poor little thing. What a stupid child.”‘

She had decided, she says, to donate her sexual and domestic services in exchange for bed and board. Ronald Bateman didn’t want to consummate his marriage, though, he just wanted ‘wife and son’ on his cv. Instead he offered his wife to his friends, telling her if she wanted to find a lover he wouldn’t mind. A ‘mean-eyed’ stallholder in the market then offered her a pair of stockings in return for sexual favours; she told Bateman who then vetted the man. She arranged to meet the stallholder, found herself trapped in his front room, was stripped, humiliated and forced into ‘painful and unwanted’ sex. Then, while she wept, he gave her the stockings.

Is Ronald Bateman dead? ‘Yes.’

Phew, in a way. ‘Yes, but I felt bad because he isn’t around to put his side. It wasn’t really his fault. Almost nothing is anybody’s fault, you come to realise. Everybody thinks they are doing the right thing.’

I get the feeling from reading her memoirs that she is amoral, or at least a morally ambivalent person. Is this fair? ‘Morality tends to be what you can afford. It’s like when I was in advertising and refused to work on a tobacco account. Had I not been able to pay the rent at that time through writing I might not have made such a principled stand.’ She absent-mindedly plays with the beaded neck chain attached to the arms of her Armani spectacles, coiling it and uncoiling it on the table. She sighs. She frowns. ‘To do things to your own advantage and at someone else’s expense seems an offence to one’s own dignity, so better not do it. I think that is my position.’

What about when she accepted the silk stockings in return for sex? ‘They weren’t even silk, they were nylon!’ She gives a snuffly laugh. ‘That was just masochism.’ She had low self-esteem? ‘Of course I had low self-esteem! No, I had a labile sense of self-esteem, sometimes very low and sometimes very high. The masochism was deeply ingrained in my psyche, as it is in all women. That is where the pleasure lies.’ She stares out of the window. ‘I’m not going to bare my soul completely but, of course, I was depressed.’ One manifestation of this depression was her comfort eating – which later became the subject of her first novel, The Fat Woman’s Joke (1967).

‘I wasn’t happy because I felt I was wasting time,’ she explains. ‘I wasn’t cut out to be a suburban housewife in Acton.’

Was her self-worth affirmed by having sex with strangers? ‘Yes. Intimate congress with another human being is very reassuring. It makes you feel alive and worthy of their attention. It’s like a drug. Heroin addicts enjoy the pimples and the dirt and the syringes and the self-disgust. The debasement is part of it.’

Her father Frank, an English doctor with a practice in New Zealand, died of a stroke in 1947. She never mourned him properly, she tells me, and she thinks this may be why she always ended up marrying men who were, in different ways, like her father. ‘Yes, that’s right,’ she says, pronouncing her ‘r’s as ‘w’s. ‘No, no, that’s not right at all,’ she adds, demonstrating another verbal quirk, a tendency to instant self-contradiction. ‘I think I always married my mother. Women are supposed to marry their fathers but actually the temperament of those they marry tends to be more like that of their mothers.’

Fay’s mother is a redoubtable woman. Once, when she came across a poem that Fay had written as a teenage schoolgirl – revealing an innocent crush on another girl – she overreacted wildly and declared that she had always suspected her daughter was a lesbian. ‘I didn’t understand what she was talking about,’ Weldon recalls in her memoirs, ‘or how I had suddenly become so loathsome: to be a lesbian was something perverse and horrible, not just something you did but what you were as well. Next day, on the No 9 tram coming home from school, I contemplated suicide – wondered how to set about it.’

Was it the sort of suicide fantasy teenagers are prone to, or had she been serious? ‘Suicide has never seemed to me to be anything other than a rational response to the world,’ she says with an incongruously fluffy laugh. ‘It’s mad not to be suicidal if you have a sense of the futility of life.

I don’t think it was a romantic fantasy. Perhaps it was. I don’t think it was depression, though. It’s like everyone saying Sylvia Plath [who was a friend of Weldon’s] killed herself because she was depressed. She didn’t. She killed herself because she was unhappily in love. Somebody [Ted Hughes] had spurned her. This is unhappiness, but it’s not madness.’

Surely love is a species of madness? ‘True. And therapists would say love is neurotic dependency, but what do they know? You have a whole range of emotions: some are pleasant, some unpleasant, but you need them both because, if you dampen one, you dampen the other. My quarrel with therapists is that they want to iron out emotions, render everything down and leave you with a lot of soupy feel-good – and that is only half living.’

Her own family’s emotions were decidedly unironed. An aunt of Weldon’s (Faith, her mother’s sister) and her own sister Jane both spent time in lunatic asylums. Given the hereditary nature of some mental illnesses, did Weldon ever worry for her own sanity? ‘No, I never felt I was losing my mind. I was too practical. Yet other people worried. And I suppose I have worried myself about patterns of behaviour. Maybe I am just in denial.’ Smile. ‘When I was growing up, insanity was the great dark fear of the age. Speaking openly about madness was not fashionable. We were more superstitious about words. If you didn’t use them, they didn’t come true.’

It is often said of Fay Weldon that, in the 1970s, she was a leading light of the women’s liberation movement, though no one can quite remember why. A few years ago, when she had a book to promote – naturally – she caused a stir by saying that she had changed her mind about women, and men. They weren’t so bad after all? ‘Men became OK. My position was reasonable in the 1960s and 1970s. It was a patriarchy, and men did abuse their power and spend their time despising women. It was a dreadful and humiliating time to be a woman. You see it in extreme example in the Taliban – the basic male attitude was not that different. But as soon as women began to earn proper wages and could control their fertility through the pill it all changed. To blame men now seems to be foolish. Women now talk about men in the same language men used to talk about women. Their only defence is that men deserve it because they were so horrid to us in the past.’

Did her attitude to men also change because she is now happily married and she wasn’t then? ‘Yes, how could it not be?’ she asks airily. ‘Nevertheless, I think there is enough truth in my position for me to universalise it.’ Well, she’s never been afraid of doing that. ‘No, I haven’t.

I sometimes take extreme positions because I want to be argued with, to see whether my position is defensible. Instead, you often get dismissed with people saying, “Pish and tosh, who does she think she is?”‘

When debating on radio or television she can seem nonchalant to the point of woolliness, but also fearless. Is this an affectation? ‘In my personal life I shy from confrontation all the time. I can’t bear to have a cross word with anyone – which is rather foolish.’

But I have read that her husbands always complained she was too argumentative. ‘Yes, they did, they do. I don’t think I am, though. It seems to me I am just putting facts forward, and when people disagree with them, which they should do, then I moderate them.’

So is she just dressing up opinion as fact – which is a rather arrogant thing to do? ‘Entertaining,’ she corrects. ‘When I do get into trouble it’s because I have abandoned truth for the sake of a witty reply. I do talk more than most people so I am bound to have a higher percentage of foolish remarks, like poor George W Bush.’

Did her time working in advertising leave her feeling cynical, in the sense that she learnt how easy it is to get away with lying? ‘No, I believed every word of it. I’m very good at self-deception. I like the material world. I like the difference between one washing powder and another. I could enthuse about eggs because I thought they were rather wholesome beautiful things.’

There is something of the insouciant, easy-natured dilettante about Fay Weldon. She doesn’t believe in doing much research: if something feels right, she thinks, it probably is. When she worked as a television scriptwriter – for Upstairs, Downstairs among other things – she would submit a first draft, wait to be asked to make changes, do them, deliver them and when she was asked for yet more changes, as she knew she would be, she would deliver the first draft again: as that seemed somehow familiar, it would, she says, be accepted at once. She is moreover, by her own admission, in possession of low taste – very much a gold taps, kidney-shaped dressing-tables and country and western music person. In her autobiography she comes across as a strange mixture of laziness, decadence and frivolity, a capricious yet rackety intellectual who is easily bored. Is it a true account of her life?

‘We all delude ourself about ourselves. One paper [a mid-market tabloid] yesterday said I was “a heartless scheming bitch”. No, what was it? “A monster.” That’s OK. I can live with that. There is an element of total irresponsible frivolity to me. But that may just be my mother’s view of me.’

Her mother was her opposite, a serious woman? ‘Extremely!’

Would Fay Weldon like to be taken more seriously? ‘No, I wouldn’t survive. At all. So, really, my frivolity is a defence mechanism. My sister was the serious one. I was the youngest child who couldn’t do anything but charm and chatter on merrily.’

And, as we have seen, contradict herself without blushing. She will make reckless assertions only to laugh them off later and she has no real consistency of thought: she used to be a freethinker, but as of two years ago she is a regular churchgoer (C of E); she was once very pro-therapy, now she is very anti; for a long time she believed passionately in ghosts, now she dismisses them as mere projections; she still considers herself to be an old-fashioned socialist yet, by her pronouncements on the purity of advertising and her endless quest for book sales, it is obvious she has now reconstructed herself as a capitalist. ‘Of course,’ she says, another conversational trope. ‘Of course people are contradictory. I see no real virtue in consistency.’

An English teacher, a friend of a friend, once said she had a shallow personality: was he on to something? ‘No. Absolutely not. On the contrary. I think it was because I would just sit and smile sweetly under attack. I wouldn’t burst into tears or react. So they would just dismiss me.’ Does that make her manipulative? ‘Yes of course. I hope so.’ She purses her plump lips. ‘No. No, I do not try to manipulate or blackmail or put thoughts into people’s heads. No. I think I’d get on much better if I did. But I can’t concentrate for long enough. My mind keeps reverting to fiction.’

She coils her beads on the table again. ‘I think women who didn’t have father figures are bad at flirting and being manipulative because they never learned to use their fathers to do their mothers down. I was no good at competing. At the sign of any competition I left.’

As a child she once accused another child of throwing sweets at her and wept until a nurse came to comfort her. ‘I knew it was an accident but preferred to be miserable, for the sheer drama of it. Later in life I’d treat lovers and husbands this way. Taking offence and suffering – knowing in my heart that they aren’t to blame, that I just wanted a drama, my turn to be victim.’

Is she difficult to live with? ‘I do often go into a world of my own and my children do complain of that and bang the table and shout: “I’m here, I’m here, I’m here.”‘

In 1996 her son Tom, then 27, was caught in possession of 15,000 Ecstasy tablets in Amsterdam. He was given a three-year prison sentence. Did she feel responsible? ‘Of course, I wonder whether I should have done this or that, but I didn’t and I couldn’t, and actually it worked out well. It did him a power of good. Prison works in Holland. They thought he was a genius. He started to paint and learn computer graphics, and came out and slipped benignly back into society. But, of course, you worry.’

She believes it is impossible to be a good writer and a good mother at the same time. ‘It is. Of course it is. And I would always be a good writer. I sometimes sent my children out in odd socks.’ She smiles. ‘Being a good mother is often a matter of public display. The Jungian view is that the child is born perfect and it is the mother who determines its character and, if it goes wrong, then it is the mother’s fault. This is a terrible burden and I can understand why the birth-rate among professional classes has fallen. Who would embark on such a task?’

Her novels tend to be dark satires on the battle of the sexes. There are few sympathetic men in them, indeed most of her male characters are callous and idle. ‘I started writing because I felt a female view of the world should be registered. I couldn’t relate to any of the heroines written by men: Madame Bovary, Anna Karenina and so on. I had not the slightest understanding of what Madame Bovary was about. I just thought, “Why couldn’t she have gone on having lovers?” I always thought there was something wrong with me, but it was the writers. Then I got good at writing novels and felt I had a duty to carry on. The fact that I am still trying to get it right more than 30 years later amounts to a failure, I suppose. But everything you do is a failure, in as much as it wasn’t what you set out to do.’

It is an unexpected comment, not least because this is a not a woman burdened by self-doubt. Perhaps it is a part of her ‘truth therapy’, perhaps it is just another example of her charming, frivolous mendacity. After all, she gives the appearance of candour but she clearly inhabits, as she puts it, ‘a world of her own’ – a fiction writer’s world.

It is time for the unserious Fay Weldon to visit her serious mother, who lives in a retirement home nearby. Her mother doesn’t come out of the autobiography in a particularly favourable light, I point out. Has she been given a copy of it to read yet? The author mouths the word, ‘No.’ A ghost of a smile. ‘Not yet. I’ve been rather putting it off.”‘