LONDON style has gone global again, writes Marion Hume. Every decade or so, the down-at-heel, throw-it-all-on originality of London street style gets swept up, commercialised and turned into big bucks. This time, the tills will be ringing for Calvin Klein.

Diffusion collections, or second lines, have become increasingly important to designers. CK Calvin Klein, reborn out of the Calvin Klein jeans mark that made the 7th Avenue designer a multimillionaire in the Seventies, is a young line. It is also, from the evidence of last Monday's collection, a London line.

It is an odd sensation to fly 3,000 miles, push one's way into a swanky salon, sit with 500 key fashion aficionados and then be shown bits and pieces that could have been put together in London's Camden Town. The only real difference was that the CK Calvin Klein version wasn't grubby.

The participants were mostly London girls, too: Kate Moss, the signed-up face of CK, whose pint-sized body is on every other bus side in Manhattan; Emma Balfour, who actually comes from Adelaide but so long ago her accent is convincingly London; Laura Roundell; and Cecilia Chancellor. They turned up for the show in the new-wave model's uniform of holey sweaters and schoolboy trousers, then, instead of emerging as glamorous, polished swans, came out looking pretty much the same.

Worn jean jackets were layered over the kind of wing-collared men's shirts London girls find in Oxfam. The boys in the show wore over-long and baggy pin- striped trousers, the kind London boys pick up for a couple of quid in Help the Aged. There was a black felt donkey jacket, just like the ones council street sweepers wear, denim vests with Rajasthani mirror-work appliques, street-market style, plus black leather jerkins. Glossy America seems to have spotted the dignity it yearns for in poverty dressing born of necessity.

Calvin Klein's greatest skill has always been to look at what is happening elsewhere and translate it into his own commercial language. That is what he was doing, with success, on Monday. He had heard that the new-wave deconstructionists in Europe were doing unfinished, raggedy seams. He put seams on the outside, but they were neatly pressed. Jeans were worn inside out, but presumably can be reversed after that whim has passed.

Klein keeps tabs on who is hot. London's Guido Palau, who specialises in the pulled-through-a-hedge-backwards school of hair, replaced the high-gloss hairdresser Oribe. London make-up artist Dick Page emphasised the no-gloss looks of Kate Moss and Emma Balfour.

So is Klein in love with London? 'Yes, yes, everything is so English now,' he told me after the show. 'No, I haven't been to London in years . . . but I love the place,' he said. What he was looking for with his London team this week was 'hair that isn't polished, make-up that looks like you're not wearing any, because now that is what's glamorous'. Funny, to Laura Roundell's mum, that all looks a bit scruffy. She probably wishes her daughter would buy a comb.

But in contrast, Klein's main collection, which will be shown tomorrow, promises to be grown-up and all-American. Lauren Hutton, the first million- dollar supermodel of the Seventies, will return to the catwalk for Klein.

(Photograph omitted)