The model agency boss who discovered Kate Moss and Sophie Dahl tells John Walsh why Princess Diana wouldn't have made it on to her books. Photograph by Trevor Ray Hart
When you're going to meet the boss of the nation's top fashion model agency, it's as well to prepare: a touch of moisturiser there, a handful of mousse ici, a suspicion of Essence de Stamford Bridge cologne behind the ears, before climbing into one's Dolce e Gabbana double-breasted and pounds 200 Hilditch & Key shirt. Then, lacing up one's Oliver Sweeney red suede loafers, and hurling an Ozwald Boateng cape over one's shoulder, one sashays down the street in that braggarty Pimp Roll beloved of male models. I tried doing it with hands hanging loose (unfortunately, makes one look like a halfwit) and with hands in trouser pockets (unfortunately, makes one look like an onanist), I affected the sulky-bastard expression, then switched to the laughing-smoothie expression, but none of it worked. People began to cross the road at my approach. It's more difficult than you'd think, being a top male model.

The Storm agency's operational centre is on the first floor of a brutally modern office block off the King's Road. At Reception, surrounded by young hopefuls, I am told to wait over there - with the girls who have a proper appointment, rather than just a "Go-See". (The young hopefuls seethe with envy.) Ranged on the sofa beneath the framed covers of Vogue and The Face, sit (left to right) one tiny Kate Moss lookalike reading Marie Claire, one Eva Herzigova demi-clone in modest decolletage reading a Frederick Forsyth novel, and one breathtakingly long girl, stretched and etiolated like two yards of spaghetti, who is clearly beyond reading anything. I cannot really sit amidst this beautiful throng (why, I might be picked, quite by accident, for a calendar shoot in the Bahamas), so I stand around sheepishly, with liquefied Butch Git styling mousse trickling under my collar.

Sarah Doukas arrives, preceded by her press officer. Model agencies didn't used to need such personnel, but it's now a full-time job. Today, the agency has fielded a hundred calls about whether it was indeed Kate Moss (and her beau, Johnny Depp) who shared the expensive champagne bath at the Portobello Hotel recently. Most of last year was spent fighting off interview requests and impertinent statistical enquiries about the luscious Sophie Dahl, who was signed up by Storm in January 1997. And the broadcasting gods have now decided that Sarah Doukas is the centre of the Nineties modelling, er, storm. She turned up on Carlton's The Truth About Women last week, explaining the lure of voluptuous models; and Tuesday's Inside Story (BBC1) follows the Storm teenage models' bid for catwalk glory in New York Fashion Week. The supermodels they hope to emulate are the icons of the last 10 years - Elle Macpherson, Marie Helvin, Rachel Hunter, Eva Herzigova, Carla Bruni, Sophie Dahl - and all of them are Storm Girls. Though she disdains the title, Ms Doukas has become the nation's numero uno flesh commissar, the woman responsible more than any other for the way women feel they should look.

Ms Doukas is a small but fruity blonde woman of 43 with an unreconstructed Sixties Babe haircut and vast, oceanic blue eyes. Having had her third child four months ago, she despairs of ever slimming down her stomach again, though she is by no means overweight. She is disarmingly friendly and honest in conversation, though she can be both gushing and abrasive about people at the same time, sometimes in the same sentence. I quoted a remark she'd made about plastic surgery ("Just a glance at Bardot proves that, if you don't succumb to the scalpel, you'll look the way she does"), and asked if she thought Brigitte Bardot's wrinkles were disastrous. "Oh, but I think it's wonderful," she breathed. That she now resembles W H Auden? "Well, it does upset me. But she still looks Bardot-y. The trouble is, you want your heroes to always look wonderful." She has never subjected any bits of her own body to radical cosmetic surgery. "No, no, look ... "(Ms Doukas twisted her lovely face this way and that, as if testing any vestigial stitches to destruction.) "I've thought about it but no, never." And nothing further south? "No. I can't think of anything worse than having something alien put into you. I do these fantastic bosom exercises instead."

She discovered Kate Moss in 1988, a year after the Storm agency began in her bedroom, and invented the Superwaif look for the Nineties. The fashion-designer world followed suit. When she'd had enough, she oversaw the rise of the Super-Podge with Ms Dahl. Did she ever feel amazed at how much fashion seemed to follow her lead? Ms Doukas is amazed by the question. "It would be very arrogant of me to think such a thing. In Kate's case, I saw her and just thought she was God-given wonderful. But she didn't actually make it for three years, and there was a lot of work. If you ask me, 'Did you think she'd be who she is now?' I'd say, 'No, I didn't think anyone would be who she is now." About Sophie Dahl she is equally modest. "I remember when she walked in, even the time, because she was sent by Izzy Blow who's very precise about time, and who warned me, 'She's not your archetypal model.' Dead on three o'clock, I looked up and saw this incredible-looking, buxom, fabulous, voluptuous blonde model and I went over and said 'Sophie...?'

"It was her personality as well as her look. I thought, if anyone could break a few barriers and taboos in this business, it would be her, because she has such a strong personality. You need one. Some people could be just destroyed by having a studio girl say to them, 'Come back when you've lost some weight.' We went the PR route with her, until people accepted her for what she was, and wouldn't start saying, 'Ooh, I think you should lose a few inches off your hips.'"

How had the image of female beauty changed in the last decade? "There's a sort of mainstream," she said, "that goes along pretty much the same, changing only a little bit here and there. But, generally, you could say that, while Eighties women were very glam and made-up and power-dressed, rather daunting and aggressive, Nineties women are more free-flowing. People look more healthy, not made-up, more accessible. The form is all health and working out and being 'perfect', whatever that may be. And alongside that, you've got the rise of trendy magazines like The Face and Arena and i-D, which suddenly focus in on somebody they want to promote, some unusual look, and many people take a lead from that." So, of the unholy trinity of fashion model agencies, fashion magazine stylists and fashion designers, who took the lead in defining a look? "Nobody really knows," said Ms Doukas disingenuously, "although a lot of model agencies claim to lead the way. It's just a combination of the three."

How interesting it is to find, amid the waifs and amazons and Teletubbies of the Storm catalogue, that the basic physical requirements of modelling remain broadly unchanged. Despite Ms Dahl ("I've been inundated with Sophie possibles, but I'd never take on another one. Because, let's face it, things aren't going to change radically, Sophie showed you can be big and beautiful, but this industry isn't going to start designing for Size 14s"), you still need to be a standard 34B-chested, 5ft 8 or 9in pubescent with wide-spaced eyes. Big lips have gone out (so Eighties) and, I'm happy to report, bosoms are back. And then there's the business of noses. Ms Doukas talked about "perfectly symmetrical faces, with a slim bridge to the nose, where light bounces off both sides". So squashy noses aren't acceptable? She considered. "You can have people with a very thick bridge, who look very pretty in the street, but in front of a camera they can look ... Really, it's got to be fine."

The Princess of Wales, I said, she had a bit of a boxer's nose. Would she have got on Storm's books? "It was a bit skew-whiff," said Sarah warmly. "So probably not, though, of course, she was wonderful." Well, well. The world's premier cover-girl, the prima donna assoluta of global fashion in her short life, wouldn't have made it at Storm? "She had the hair, and the body, and the height and the legs," said Ms Doukas, defensively, "but, for Storm, in terms of what we're specifically looking for, no. The whole world will criticise me for saying so, but," - she took a deep breath - "for us, a nose cannot be an issue in a picture. I'm not saying she had a big nose, it was just a bit wonky. And her mouth was a bit small. Not wide enough." She giggled. "We are terrible here. We're medicinal about the smallest details." I think she meant "forensic".

The connoisseur of commercial female beauty was born Sarah Chambers in Malta but grew up in the New Forest. Her father was a surgeon in the Navy, her mother a pharmacist. "Both medical, you see - no wonder I'm always dealing in flesh," she says. I suspect it had more to do with her father's lack of appreciation of his lovely daughter. "He was awful to me, really. He used to tell me I was quite hideous. He was really naughty. I remember once, when I was 15, he had TB and used to go to bed early. I was going out so I went into his bedroom to say goodnight, and he said 'Oh - you're actually beginning to look quite pretty.' It was the only compliment he ever gave me, after always being quite rude." Things were no better when it came to studying. "My father was such a terrible intellectual snob, he used to railroad me all the time about bad reports. In the end I thought, I've had enough. I'm off. I left school just as I was about to take my A-levels. I mean literally a week before. I just ran away. 'Stupid girl,' my father said, 'You'll be no good. You'll come to a bad end.'" She laughs, slightly too emphatically.

The rebel became a model in the early Seventies after a photographer friend took some pictures of her to an agency. "They called me in and said, 'Christ, you're far too small', and I said, 'Yes I know, I don't know why I'm here.'" But they took her on anyway and she stayed for seven years. She recites the dizzying multiplicity of her modelling CV as if reporting from another world. "I did facial stuff, and body stuff and commercials for Harmony hairspray. I did shoe catwalks, because I have small size-four feet, and I did car modelling - tall women wouldn't fit inside cars, but I fitted quite well - and absolutely my worst assignment was a commercial for Townsend Thoresen Ferries, where I had to dance about in a pink bikini with a script about 100 words long, being followed by cut-outs from the Pied Piper." Mostly she hated the whole thing, though, because at 5ft 2in, she wasn't tall enough for most of the sessions. Her safety valve was an antiques business at Antiquarius in the Kings Road, buying and selling English boxes ("What kind? Music boxes, writing boxes, pewter, shagreen, sharkskin - every kind of box you could see"), whither she would rush at the end of a modelling session. She ran a stall in Paris for two years, before coming home to manage a punk band called The Criminals who almost, but not quite, got signed to Virgin. "I was very good at setting up the drum kit and driving the long-wheelbase Transit everywhere. The band were mostly out of it all the time. It was hopeless. I loved it." Were they any good? Confusingly, she reports, "They were fantastic, actually. I thought they were great. But, of course, it was just a lot of screaming and shouting and crazed." My dear, the noise. And the people. Later, at 32, she walked out of a job as "booker" in the Laraine Ashton agency and started up Storm with some financial help from Richard Branson.

She comes across today as a kind-but-firm mother bunny in an often heartless industry. The younger her charges get, the more they need Ms Doukas's common sense and unpretentious tutelage. Ask her what she'll try to change about her models, apart from hair, teeth, skin and make-up, and you get a long, careful diatribe about eating habits. "I'm very wary about weight loss," says Ms Doukas. "If you feel that someone's natural weight is rather more than their actual weight, you don't touch them. But if someone has a wonderful face and is slightly overweight, I'd ask her what she ate. I don't believe in dieting, I don't think it works. But I'd say, Go away and have a breakfast, then don't eat until 12.30pm, then eat something decent, not a Big Mac or 50 Hob Nobs, no sweets in the afternoon, eat early in the evening, take some exercise and we'll see you in a month. But it's very difficult to say that to a 16-year-old, who's quite likely just to go off and starve herself."

The maternal Sarah has no time for the "heroin chic" stylings beloved of certain fashion magazines and condemned by, among others, Bill Clinton. "I'm glad that's gone, I really am. I thought it was unacceptable - and I don't know who it was supposed to be appealing to." Ditto the tearful- and-shagged-out look briefly imposed on his models by the late Gianni Versace. All in all, Ms Doukas is somebody you'd unfailingly trust to steer your nervy, knock-kneed 14-year-old into a new generation of bewildering body contortions and heftily-maquillaged facial display. Just send in those photographs, be prepared for disappointment and remember the simple guideline: the nose cannot be an issue