A come-on, or a kind of armour?

Why does a woman wear a low-cut dress? The answer seems obvious, no? But if that's what you think, you may be wrong. By Ruth Picardie

Earlier this week, a female barrister declared that women who wore revealing clothes in public were inviting male attention. "If a member of the public, whether royal or not, is willing to go into a public place showing a low cleavage, it ill behoves anyone to criticise the taking of a picture," declared Jacqueline Samuel during her defence of a former Harvey Nichols security guard who secretly filmed the Princess of Wales on a visit to the store, lingering lasciviously on her legs and decolletage. "It is no offence at all to take videos of people who wear low-neck dresses in public places," she said. "It is not as if he climbed over the wall of Kensington Palace and stuck a video camera through her bedroom window."

Yesterday, there was an outcry from other professional women. "To suggest Diana - or any woman - was inviting it because of the way she was dressed is quite disgraceful," said Janet Anderson, Labour's spokeswoman on women's affairs. "I can see the point she was trying to make," added Alison Parkinson, chairwoman of the Association of Women Solicitors, "because it is not an offence to film anyone in public, but it was unfortunate she used these words to make it."

Women (not to mention men) seem to have become very muddled about sexy clothes. For here we have two groups of successful post-feminist women implying precisely opposite things. The first, nonagenarian judge-style, suggests that women who go out in revealing clothes are asking for it; the second that dressing like a sex object is part of a woman's right to choose. What on earth is going on?

Women and clothes used to be so simple. Until the Sixties, there were good girls and bad girls. Good girls like Doris Day wore pastel knits and sensible shoes and bustled unsexily about in the kitchen. Bad girls like Jayne Mansfield and Marilyn Monroe had huge upholstered breasts and skirts which flew up over subway grilles, but were punished for their sexual allure, becoming victims who died young.

The rise of the professional, post-feminist woman in the Eighties broke that paradigm apart and created a third female category: the honorary man, accessorised with briefcase, sharply tailored jacket and American footballer-size shoulder-pads. She was Sigourney Weaver, the bitch-from- hell boss in Working Girl, the frantically successful Diane Keaton in Baby Boom. ("I can't have a baby," she says, "because I have a 12.30 lunch meeting.") The patron saint of this new power dresser was, of course, the super-tough Margaret Thatcher, whose voice became deeper with each passing year.

To some extent, this stereotype still stands. "My customers have had to work twice as hard to get where they are," says Joy Weinrabe, general manager of Wardrobe, the style consultancy for professional women. "They're not going to throw it away by showing their knickers. Skirts can be no more than slightly above the knee. Necklines must be conservative. Otherwise they wouldn't be taken seriously by the men. Though you can be prettier, now," she adds, "wearing softer fabrics under the jacket. The old aggression has gone." Andrea, a 30-year-old executive in the pharmaceuticals industry and Wardrobe client, concurs: "I can think of one woman who wears very high heels, and that's it. You certainly can't show any cleavage."

Sally Brampton, fashion writer and founding editor of Elle, agrees. "In the Eighties, men's suits became more feminised - often by "designer" ties - and women's skirts got shorter," she says. "But see-through blouses are still unacceptable. Men and women find it distracting. Similarly, if a man came into the office in tight trousers, his colleagues wouldn't take him seriously."

But, since the late Eighties, the meaning of sexy clothes has been breaking down. While unthreatening bimbos still get their tits out for the boys on Page Three, a new dress code has emerged, a product of second-wave feminism and the fact that, in Sally Brampton's words, "We are becoming increasingly desensitised to eroticism." Madonna took her clothes off in her book Sex, not to please men but as the personal expression of one of the richest performers in the world. Sharon Stone didn't wear any knickers in Basic Instinct, but rather than being punished for her desire, she ended the film on top of Michael Douglas, ice-pick to hand. Iconic American Vogue editor Anna Wintour is rarely seen in anything other than a micro- mini but, accessorised with indoor shades, the look is less inviting than armour-plated. Working girl has merged with bad girl to create post-feminist babe, who puts on her Wonderbra in the morning and says, "Hello, girls."

"The post-feminist babe uses her sexuality," says 24-year-old Katie, whose signature outfit is see-through shirt and colour-co-ordinated bra, "rather than finding herself being used for her sexuality. I'm far more aware of women's reactions to me than men's. If I am attracting men, it's certainly not my sole motive." Clare Pizey, 31-year-old series producer of Desire, Channel Four's frantically hip new show about fashion, agrees: "Sexy clothes are all about making women feel good about themselves."

All this explains the protests against Jacqueline Samuel: legs and cleavage are now the liberated woman's uniform. "Sexy clothes empower women," says Lorraine Gamman, lecturer in product and fashion at Central St Martin's, "from the dominatrix down." And, according to this reading, while these clothes also symbolise a throwing-off of the shame that surrounds women's sexual appetites - what Gamman calls "the oppression of the slag" - men's reaction to cleavages in the office has nothing to do with their animal instincts being roused and everything do with fear. Sally Brampton concurs. "In most blue-chip institutions, trousers are still not acceptable. Why? Trousers are simply a relaxed form of dressing, but men resent women encroaching on their territory." Hence the success of the power dresser: feminine, unsexy and safe.

There's a problem with all this theory, however, which Lorraine Gamman expresses this way: "The average man has no access to post-modernism." Hence the Harvey Nichols "video rat" who thought he was getting good old- fashioned t&a when actually he was getting a look- but-don't-touch post- feminist babe.

"Men aren't very subtle, are they?" says Katie. "I'm always telling blokes I've got a degree. Almost every day workmen mutter, 'Nice tits' as I pass. 'Fancy a snog?' is another popular one. On Saturday I went to a festival with my boyfriend and a ticket tout said to me: 'Fancy a bunk-up? I've got the biggest dick in London.' What a turn-off."

And, it has to be said, it's not just men's fault for misreading the new codes: sometimes, the post-feminist plays it both ways with neanderthal lust. "It's really ageist and really good-looking-ist," says Katie, with sterling honesty. "If the bloke is old and ugly, their comments are a violation. If they're young and handsome, they're a compliment."

Of course, there is another theory. "I don't think dress codes are about gender any more," says Clare Pizey. "Men and women in the City wear dark suits to work, that's all. Men don't wear Hawaiian shirts; women don't wear mini-skirts. The only reason Princess Diana gets attention is because she's so sexy. She'd look sexy in a paper bag."