SHIRLEY CONRAN'S sea- front flat in Monaco is located, appropriately enough, between a dress shop, a bank and a disco; and the biggest of these is the bank. This neatly sums up the rewards offered to the heroines of her blockbusters: clothes, money and pleasure. But the biggest of these is money.

Money is what Monte Carlo is all about. The seductive, fin-de- siecle casino is the most beautiful building - some would say, the only beautiful building - in this tiny principality that lies seven minutes by helicopter from Nice. Monaco's three-quarters of a square mile is as overcrowded as a South American favela or shanty town, its concrete multi- storey blocks climbing up the sides of cliffs that drop steeply down to the Mediterranean. Here, a view immediately over the sea is the first thing that defines status; a good square- metreage of living space is the second. Shirley Conran has both in abundance.

She has lived here since the winter of 1979/80, when Anthony Burgess, a friend and long-time resident of Monte Carlo, suggested that instead of living modestly in a two-room basement in north London for pounds 120 a week, she could pay less rent and live in more comfort out here. We are talking on her balcony, scented jasmine dangling above our heads, fresh coffee and strawberries on the marble table between us, and the sound of happy shouts drifting up from the bathers on the beach. It is easy to see why she came, took one look, agreed with him, and stayed.

She is wearing a light blue shirt and trousers and a whopping great aquamarine ring. The ring - as she probably intended - is the exact colour of the sparkling sea. She is tanned, with short hair streaked blonde. At 60, she looks pretty good. As the writer of four worldwide best- selling blockbusters, you might think: 'She can afford to]' So she can - but she earned it the hard way.

The Conran name is famous nowadays as much because of her as Sir Terence, her first husband; with additional help from their two sons, Jasper, the dress designer, and Sebastian, the designer full stop. That Shirley deserves her fame is the very heart of her philosophy. If women want power over their lives, they must earn and hold on to their own money.

This is also the theme of her fourth, latest novel, Crimson, whose message might be summed up as 'Daddy doesn't know best'. Women's vulnerable point, she says, has always been their tendency to hand responsibility for their lives to a man. Men know this, and exploit it ruthlessly. Men use sex, or violence, or infidelity, or bullying, to gain control over women and help themselves to their money. Readers of her novels may think they are reading steamy sex 'n' shopping blockbusters, she says, but actually they are reading feminist tracts. I would have laughed at this had I not spent the flights to and from Nice and half the night in Monaco reading Crimson. It is a feminist tract.

'My themes are subliminally expressed. I don't want it to be realised that I'm writing teaching books - I'm writing sexy novels, thank you very much. My books are subversive: but by giving the message in parable form, I hope women can accept it. The trouble is, women still think power is a dirty word, that it means Hitler and jackboots, but it doesn't; it means control. Crimson is about not handing power over to men.'

The men boarding the 8am flight from Heathrow to Nice had crinkly brown, semi-handsome faces. They were dressed like retired pop stars trying to look like retired admirals. The women with them seemed too young to look so old, until you got closer and saw that their artlessly windblown hair was coiffed into rigid little spikes and their gleaming faces could not move much. They wore enough jewellery between them to open a small branch of Cartier. They looked very rich, very pleased with themselves, and not very nice.

Such people are also the denizens of Shirley Conran's novels. She knows their world well and writes about it convincingly - the yachts, the chateaux, the glossy, bitchy parties in Hollywood and New York, the private showings at art galleries or couturiers' salons - been there, done all that. She believes that women deserve better and she is her own best advertisement for what that might be. After some tough patches and three failed marriages, Conran has undoubtedly taken control of her life.

So let us scamper through her past. Born 1932, christened Shirley Ida. Hang on . . . Why Ida?

'My great-grandfather was mad about opera and he and his wife used to go a lot and he named all his children after operatic figures. I have a great-uncle Siegfried and a great-aunt Norma and my grandmother was Mignonne.'

Her father drank too much, and was violent when drunk. This has given her a lifelong docility towards male bullies and marriage, she says, turns her into a doormat. But she went to a good school: St Paul's, in Hammersmith. She was there at the same time as the artist Gillian Ayres (who is still a friend and gave her a wonderful painting for her 60th birthday). From here Shirley went to Portsmouth art college.

She met and married the young Terence Conran when she was 23 and a fabric designer, and was soon in charge of Conran Fabrics. Their first son, Jasper, was born in 1959, when she was 27 and Terence 28; then Sebastian, and in 1962 they divorced. Interestingly, Terence Conran's Who's Who entry mentions the two sons but not the name of their mother: silly, really, since her entry is directly above his and she names him. But then, Shirley Conran has been married twice more, and her entry doesn't mention either of those husbands.

After the divorce she found herself with two little boys to bring up, inadequate child support, and no job.

The tables and bureaux in her breezy cream and white drawing room are covered with family photographs. There is handsome Jasper (looking so like his mother) and Sebastian with his wife and baby Sam, their first son; there are weddings and smiling groups; there are friends '. . . that's George, my editor at the Observer . . . that's Bruce (Chatwin) - he died in my house in Provence, you know - that's a little silver box he always carried: Elizabeth gave it to me . . . ' Shirley Conran probably lives alone these days because she prefers to, not because she has to.

From design she turned to journalism, becoming woman's editor of the Observer colour magazine, then of the Daily Mail, then of the magazine Over 21. Her conversation is peppered with references to what she learnt from all her mentors. It adds up to two things: discipline and research. She knew lots of interesting people in Sixties London, joined an early feminist group called Women in Media and was put in charge of the publicity for its campaign for legislation against sexual discrimination. She was always tired, of course - young mothers with jobs always are - and in 1970 illness struck.

'I was ill for a month in hospital with viral pneumonia and unconscious for five days, and after that I got post-viral syndrome and was unable to work. There was just no energy there. It was like trying to start a motor-bike with a flat battery. I had no savings and amazingly quickly I found myself having to leave the house I'd bought in Regents Park Terrace. I didn't sell it - I let it, which paid the mortgage and the interest on money I had borrowed; and then I lay down - I couldn't sit - I lay down and wrote Superwoman.'

That book, which told women how to do the minimum amount of housework for maximum effect, was a publishing phenomenon. It went into seven editions in six months and sold 75,000 hardback copies. 'It was a learning process for me. Despite its success, I hardly got any money back. I had an advance of pounds 2,000 and almost all that went in typing and research costs. The publisher took a huge share of the paperback rights. It taught me to scrutinise contracts.' Four more Superwoman books followed.

'Then, when I decided to write an international book, I needed an American agent and I chose one who was a lawyer as well. Meanwhile, the PVS went on for years. My doctor said, 'Oh, it's mental: go and see a psychiatrist'. He thought it was because I was lazy and trying to avoid work. I knew it wasn't that: I loved writing. In 1979 I decided I could stake myself for one more year and after that I'd have to go back into design or business.

'At this point I met Anthony Burgess, who said, 'Why don't you come out to Monaco?' and I thought, 'What a wonderful idea]' I was visiting Mary Quant, who's got a house in Nice, so I came along here and I quite knew what he meant. I went back to London, packed my suitcase, put a few things in the car, and came down here with just a desk, a folding bed and a typing chair. That was all I needed.' She found a one-room studio flat in the block where she now lives and paid pounds 35 a week in rent and pounds 9 for food.

At this point we leave the sun- soaked balcony and descend two floors. 'I've never shown my office to a journalist before,' she says. It, too, overlooks the sea; a long, narrow room lined with reference books and office furniture. It looks like the bridge of a ship - functional, with not a single object or picture to distract the eye. It is a machine for working in. There are filing trays stacked up six or seven storeys; a word processor and a printer; a fax machine, and files and files of immaculately labelled notes. She finds one, 'Feminist themes in SIC's books', and holds it up. 'Do you want to read that?' It begins: 'The theme of all SIC's books is self-confidence in women: how to get it, lose it, regain it and keep it.'

Shirley Conran is confident about her books because of the thoroughness of her working method. 'It's called 'creative visualisation' nowadays, but it just means using your imagination.' Before starting to write she makes notes on the plot, sub- plots and clues; on her characters' chronology and whereabouts; she photocopies a calendar for every year covered by the book to get days of the week accurate; she records the weather, the locations, story, development and themes of all her novels. This stage takes about two months, by which time she has a total plan. It takes her about five months, working from 9am- 6pm, seven days a week, to write it. 'But if I feel tired, or Bernard Ashley invites me down to St Tropez,' - she laughs - 'then off I go]'

Until last year she wrote by hand, often as much as 400,000 words, which then had to be pruned to the standard blockbuster length of a quarter of a million words. It is an awesomely efficient method but it looks cold and bloodless, more like science than art. The careless rapture of creativity is not much in evidence, but then, Shirley Conran despises carelessness. 'No 20-year-old,' she says, 'could write like me. They haven't viewed life or known its bitter element.'

So what was the feminist theme of Lace, her first fiction book and a worldwide best- seller? 'Lace was about sex from a woman's point of view. I was frightened of writing it. This was 1979/80, and I was so sick of reading male writers getting sex all wrong. Hemingway writes 'and the earth moved for them' and one can't see why it should have moved for her. So I had four heroines, each with different sexual responses, and I did a lot of research among my women friends, asking them to tell me what sex was like for them. I didn't acknowledge them by name, of course. We've come an awful long way since Betty Friedan, but we've got the indoctrination of centuries behind us. In 1968 we were in the Dark Ages. You can't go from that to becoming astronauts in 25 years . . . though some of us have.'

Lace was written in 1980 in her studio flat, now her office, where she lived and ate and slept until its publication. Did she always know that it would be a success?

'The first person ever to read Lace was the head of the Princess Grace public library; a professor of English called Dino Sanpulescu. Anthony Burgess introduced me to him. When Dino gave me back the manuscript and said, 'This is going to be a worldwide best-seller,' I thought he was being kind. It was going to be auctioned, but Simon & Schuster made a pre- emptive bid of three-quarters of a million dollars, an awful lot of money in those days.'

So, after that, she knew she had no more money problems? 'I knew I would never have to worry about how I could afford to live ever again, yes.'

You have enough money to stop work forever now, if you wanted to. Why don't you? She smiles.

'Because I'm a writer. And because it's a big responsibility, being a big earner. The publishers have invested money in you and they expect you to perform.

'In my teens, money was a dirty word. My parents would say, 'You get everything paid for: what do you want money for? Be grateful for what you've got.' But what women experience is that money can make unhappiness a great deal more endurable; 99.9 per cent of the goddam globe belongs to men. The importance of money is played down to women - but if it's so unimportant, why have the men got it all?'

(Photograph omitted)