Miles herself, though, was anything but worried. Indeed, she took great delight in confessing to her friend that the offending supermarket shelf- filler, Return to Eden, was hers, and moreover that she was proud of it. With the publication this month of Guenevere: The Queen of the Summer Country (Simon & Schuster, pounds 9.99), an unashamedly romantic saga set based on the legendary Knights of Round Table of the first millennium, Miles will once more be shattering the illusions of those admirers who want to preserve her in aspic as a home-grown version of her near- contemporary, Germaine Greer.
For this is bodice-ripping, breast- heaving, heart-fluttering stuff. When the golden-haired queen yields to her king, Arthur, in a moon-soaked glade of wild honeysuckle, the novel quickly establishes itself as a top tip for the Literary Review's Bad Sex prize. "Arthur drew in his breath in bliss. He might have been born for this minute, and he wanted to hold the joy of it for the rest of his life. His hands slid blindly down her back and with a sigh of wonder he took her by the hips. `Such a little waist,' he said... He entered her, and she felt a shaft of pain. Then a triumphant burning grew in her and spread till her whole frame throbbed with fire. A raw cry burst from her throat."
In the flesh, as it were, Miles herself appears much more the stereotypical fragrant romantic novelist than a Greer clone. She welcomes me to her achingly beautiful Kent manor house in an elegant floaty, flowery, full- length dress. As we munch our way through hand-crafted shortbread, the conversation glides over the (for her) joys of silk underwear, the potential benefits of cosmetic surgery and onto the second and third instalments of the Guenevere trilogy, currently in preparation.
Yet as quickly as she has conjured herself up into a living, breathing Barbara Cartland heroine, Miles dispels the image. As well as the Guenevere novels, she is busy putting the finishing touches to her next book, A Women's History of the Twentieth Century. She drives racing cars round nearby Brands Hatch, has trekked through a desert on a camel and spent 14 years as a contributing editor to Cosmopolitan.
The new novel is scarcely, she points out, painting Guenevere as some shrinking violet waiting to bloom under the caress of her man. A queen in her own right, her Guenevere descends from a line of queens who enjoyed the ancient right of "thigh- freedom" - to take up and then discard whatever man they please.
"I wanted to recapture the active, regal women of this period," says Miles. "The only one we all know is Boadicea and we remember her because of her failure." Her two women's history books have given Miles pole position as the reverser of time's neglect when it comes to feminine exploits. She performed a similar trick for Elizabeth I in her novel I, Elizabeth, which moved beyond conventional descriptions of the monarch's political savvy and flirtations with her favourites to tell in romantic terms of her enduring lovers and, in particular, of her passion for the youthful Earl of Essex.
Would it then be too crass to describe Miles's new novel as a feminist makeover of the Arthurian legend, placing a liberated woman at its centre? Miles has problems with the word feminist.
"I think feminism's time has passed," she says. "It's not passe, just passed. Thirty years ago we were fighting for equal pay, equal opportunities, free contraception, and we still haven't got them all. But, because of feminism, those issues have been addressed, progress has been made, prejudices shifted, the struggle diffused. And in the sense that society now accepts that what we used to call women's rights are human rights - equal pay and equal access to work, for example - then we are all feminists now."
To many erstwhile colleagues this may sound like a betrayal, but Miles was never a universally liked sister. Her refusal, she recalls, to renounce men in the heady days of the Seventies caused her no end of trouble. Yet there are other, more technical, less philosophical problems, with labelling Miles's Guenevere a feminist hero.
Though the author's twinkly blue eyes are flashing when she talks about the lost tradition of women warriors - "did you know that their used to be a war school in Chester for women before the Christians suppressed it in the sixth century?" - she does not let her queen go into battle.
"It was the biggest dilemma I had with the book," she explains. "Should she fight from her chariot like, say Boadicea? Initially I had her down as a kind of Pansy Potter, the strong man's daughter in The Beano. But then it would have been impossible to follow that with her melting into her lover's arms.If you learn to kill, you of necessity lose some of your humanity and she would lose sympathy as a romantic figure."
It is, I realise as the afternoon rolls on, a typically Rosalind Miles remark. There is the populist (almost) contemporary cultural reference to Pansy Potter. And then there is the observation of human behaviour that is presented as a rule - if you kill, you are less human. It's not that I necessarily disagree, though someone like Leonard Cheshire might have done. Anyway, Miles has a formidable five degrees covering literature, history, sociology and psychology behind her. Rather, it's the way she presents her brew of received and folksy wisdom as gospel.
It all somehow emphasises the uneasy middle ground that Rosalind Miles holds between being a clever scholar, and a popular commentator and novelist. Though she admits she is "a cock-eyed optimist", she remains determined to have it both ways. "I don't know why writers have to be pigeon-holed," Miles says, "but people long to do it. Feminists have to be hatchet-faced and far removed from romance and erotic melodrama, and romantic fiction, by which most people mean women's fiction, is somehow assumed to be a lower form than academic books, but all the things I have written about are my life, my interests... They're me, my stuff. You can't split me into categories."
There is a pragmatism too in her approach to writing novels. "Fiction reaches more people. With Women's History of the World, I was preaching to the choir; readers would have had a prior interest. Guenevere is for people who wouldn't pick up non-fiction, who think they don't need me, but who will find out when they read it that they do."
It sounds curiously arrogant, but perhaps for once Miles's grasp of words has failed her. For she doesn't overestimate her achievements but is merely - and rather unEnglishly - not shy about talking about them. When I ask her about her previous books, she pops upstairs, brings a heap of them - 16 in all - and puts them on the sofa next to me.
Such directness is just part of her character. Her refusal to pretend to be other than she is, I imagine, the product of having had to fight rather harder than some of her male equivalents on the way up.
Fiction may have been her first love - she wrote her first story aged 10 - but when she started out, she had to balance writing with her academic work, her marriage, household bills and her two youngsters. Non- fiction brought a healthier return on the basis of work that she had already done for her theses, so "thrifty girl that I am", the novels had to wait.
The omens for a more mature but freer Miles, fulfilling her desire to lead a double literary life, are mixed. A small number of writers have succeeded. Between heavyweight history books, Antonia Fraser pens frothy Jemima Shore detective yarns. Erich Segal combines tear-jerkers like Love Story with tomes on classical civilisations. Philippa Gregory is another author to manage the popular-academic mix. Yet, like it or loathe it, the desire to put every writer in a box remains strong, and chameleons are correspondingly few and far between.
Rosalind Miles, a biography
Rosalind Miles was born in Warwickshire. She received the first of her five degrees from Oxford and then studied at the University of Birmingham, where she subsequently taught English before setting up the Centre for Women's Studies at Coventry Polytechnic. In 1974 she published The Fiction of Sex and followed it with a number of well-received literary studies based in the Elizabethan/Jacobean period, including two books on Ben Jonson. At the same time, she wrote more polemical books on social and historical themes - The Rites of Man, The Children We Deserve and A Women's History of the World - and in 1984 published her first unashamedly romantic novel, Return to Eden. She has been shortlisted for the Philippa Fawcett, James Tait Black and Whitbread prizes. A familiar face on television and radio, she now lives near Faversham, Kent and lectures on both sides of the Atlantic.