Stand back Karan, Lauren and Klein

The world of the American fashion designer Tommy Hilfiger will be unveiled in a catwalk show at the Royal Albert Hall in London today but it will matter little if the audience likes it or not - Tommy Hilfiger's push for our hearts and minds will not be fought on the pages of Vogue but on the pavements and in the clubs.

If Hilfiger's lifestyle conquest of Europe goes according to plan, as it probably will given the mechanical precision of his US operation, we will soon be living in a red, white and blue Tommysphere, working in and working out in Tommy wear, snoozing in Tommy sleepwear and smelling of apple pie care of Tommy: the New American Fragrance.

Forty-four-year-old Hilfiger is the current success story of American fashion. Since 1992 the company has grown into Wall Street's favourite frock stock and last year it turned over $480m, buffeting the established heavyweights of Donna Karan, Ralph Lauren and Calvin Klein.

But unlike his competitors, what Hilfiger offers is not so much the clever re-modelling of European fashion in the name of ease and lifestyle, but a brand of hip, affordable "urban prep" derived from the melting pot of American life.

Whether we are ready for Tommy Hilfiger's brand of "classics with a twist" depends on how far we are willing to be seduced by the heavily branded style of casualwear and its attendant images of wholesome fun and promises of popularity. The name already signifies the height of cool among black club kids and though Hilfiger's genuine brand clothes are not yet available, counterfeit merchandise is in high demand.

In an inconspicuous building in midtown Manhattan, Tommy Hilfiger employees move purposely from room to room as his assistant - one of eight - greets visitors profusely. "We're very excited, to be honest, very excited," she says, bearing gifts of the new Tommy fragrance and a 10 Years of Tommy promotional video.

Soon enough Tommy himself glides over, projecting the kind of friendly ease that is simultaneously winning and alarming. Slightly built, he is as fresh-faced and clean-cut as an all-American boy could be. From his page-boy haircut and whiter-than-white caps of his tombstone teeth, his open white shirt and blue chinos to his shiny black penny loafers, he is put together in precisely the look that has taken America by storm.

Not surprisingly, his spacious office is spotless and filled with the paraphernalia of a boys-own dream - NFL football helmets, antique military regalia. Behind his desk hang huge photographs of Mick Jagger and John Lennon; on one wall is a set of splashy paintings by David Bowie; signed guitars from Ron Wood and Steve Winwood take pride of place alongside one another. Tommy sits behind an imposing oak desk, swivelling in his raised chair and looking down upon visitors who sink helplessly into the huge chairs opposite. He looks like a cross between Captain Scarlet and the Cheshire Cat.

What makes Tommy tick is not easy to tell by meeting the man. Tommy's tick, such as it is, is an enveloping all-American corporate ethos, expressed in the third person, channelled with an unbreaking gaze and illustrated with hand gestures.

"Tommy is classic but updated, modern, athletic, functional, accessible. It is bright, fun and full of life and spirit," he says. He could be talking about himself. "We develop themes around our groups - snowboarding, surfing, along with sailing gear, baseball. And we also contribute to my fondness of English sports. We do a cricket group."

Cricket? In America?

"Well, it's really tennis-golf but we call it cricket because maybe we use more cricket-type colours."

It's soon clear that whatever line one takes - gentle banter, direct questions - the result is the same. Tommy is a walking, talking press release. His delivery is classic image projection that makes the head spin and the heart sink. Project the image, points one, two, three. Project the image, project the...

"We believe we have a world class product ... we've done it in a different way ... it's incredibly high quality and great style but American style that translates into global style at affordable price points ... accessible to the world."

Ho-hum.

Tommy's professionalism even runs to memorising a "face book", a kind of corporate Who's Who, so that he can greet every employee in each of his 840 outlets by name on his frequent in-store promotional tours through the malls of America.

Wherever he goes he is treated like one of his rockstar heroes and is shadowed by a private security detail. He obviously enjoys the attention and knows the value of keeping in touch with his customers; an aide always trails him with signed photographs for Tommy to give to his fans.

There is little to suggest that there is much to uncover about Tommy, what you see is what you get. "There's just nothing incredibly mysterious," he says somewhat apologetically. "In fact, I'm more normal than people would like. They might like something more juicy or interesting with my background or my life. But I am who I am."

To many he is a relentless self-promoter who provides a corporate face for his corporate name - which, in a Faustian but not uncommon pact in the fashion business, is owned by his backer, the Hong Kong-based textile magnate, Silas Chou. In exchange, Hilfiger owns 22.5 per cent of the company (valued at $100m) and enjoys an annual salary of $6m. For that he must maintain appearances and avoid controversy.

He gives to charity, he uses his Gulfstream II jet for business only, he likes fishing, cycling, skiing, wide open spaces, his house on Mustique. He lives with his wife of 16 years, Susie, and their four children in a 22-room colonial farmhouse in Greenwich, Connecticut, decorated by Colefax & Fowler.

In fact, all one can know about Tommy is already on the promotional video that cuts between film of Tommy aged four and Tommy now, discussing what it was like then.

We learn that he grew up in Elmira, a small town in upstate New York, as one of nine children. That in 1969 he started his first business, a chain of upstate New York hippie boutiques called People's Place, with just $150 and 20 pairs of denim bell-bottoms. Having opened 10 stores by 1977, the company hit hard times and Hilfiger was bankrupted.

He then switched from retailer to freelance designer before forming a partnership with Mohan Murjani, an Indian investor, and launching his first cheeky assault on the orthodoxy of American fashion by pitching himself as a younger Ralph Lauren. Before bailing out of that deal in 1988, he opened an unremarkable and short-lived shop on South Molton Street.

Sartorially at least, Tommy Hilfiger has something for everyone. He counts among his custom the presidential celebrity of Bill Clinton (who wears his ties), Snoop Doggy Dogg (who favours the extra-large streetwear), Prince Charles (whose framed letter of appreciation for a delivery of freebies is in Tommy's office), Fergie (who likes to fly in his jet), singer Bjork and rockers Metallica.

Though no one knows why Tommy's bold logos have become totems of black urban cool, he's now cashing in on an invaluable cultural cachet for all it's worth and has enlisted producer Quincy Jones's daughter and rap impresario Russell Simmons to help keep rappers coming his way.

Rapper Q-Tip even included him in a song."Tommy Hil was my nigga/ and others couldn't figure/ how me an Hilfigga/ used to move through with vigga." High praise for a suburban white boy who presents himself as a regular guy designing for other regular guys and soon, girls.

As the self-described antithesis to the Parisian catwalk designers, he does not seek the mercurial "moments" so beloved by the fashion pack and, as a result, has suffered bouts of the silent treatment that is their preferred signal of disapproval.

Last year, in what was perceived as a tacit rebuke, the Council of Fashion Designers of America refused to give any award in the men's category at their annual awards ceremony. Though he was awarded Menswear Designer of the Year in January this year, he remains a subversive to the industry - no heroin chic, no jumping on fads, just consistent development of signature lines.

"There is the trendy fashion business that has to do with people being in business one minute and out the next and I'm not in that race to see who can be funkier or more eccentrically creative," he says. "I choose to think we are running an apparel business run on a combination of product, marketing, placement, strategy and profitability."

Despite the sniffy - probably jealous - reaction of fashion's elite, Hilfiger understands the business as one of margins and volume, and gives his customers what they want, not what he thinks they should want.

Perhaps this is a failure of imagination, but as other more modish fashion sales have slipped his have risen. So when the crowds pour out of the show today they may, against their better judgment, have seen the future. Tommy's radar is, as he says, "in tune". When his first store opens in Harvey Nichols early next year the customer will be able to decide.