Matthew Williamson's marvels

Should he stroll down to Regent Street at 9am, hide behind a lamp-post (Lord knows he is slim enough) and watch the chaos that ensues when the doors to H & M's flagship store swing open to unveil his new collection for H & M?

"I don't know what to expect. I'm very humble about it. If people turn up, I'll be thrilled." turn up?

Such modesty. By the time you read this, the shop floor will be a veritable rugby pitch as scrums form around £69.99 tuxedo jackets and £49.99 jersey shifts. this, the store's sixth collaboration with a designer (previous collaborators include Karl Lagerfeld, Stella McCartney, Roberto Cavalli and, er, Madonna) is surely destined to be a sell-out, for who could resist a slice of Matthew on the cheap?

With pieces from Williamson's mainline collection typically costing £1,500 and upwards, this is the ultimate credit crunch buy.

Designer/high street link-ups are a peculiarly British phenomenon, and one that shows no sign of abating.

This week alone, Giles Deacon launches his latest collaboration with New Look, while former Biba designer Barbara Huliniki debuts a collection for topshop. "Everybody needs to be looking for survival mechanisms," says Williamson.

When we meet at his Mayfair HQ, Williamson is tanned from a recent holiday with Sienna Miller: just the two of them, in Turks and Caicos. "Well, it started with just the two of us, but by the 10th day there were 10 of us. We had this amazing villa with loads of spare rooms."

Of an evening, Miller would amuse the party by acting out the various parts in Williamson's lavish new TV ad, which culminates in him emerging out of a spaceship like a camp James Bond. what a thrill, I suggest, to be starring in your very own telly ad.

"H & M have budgets for media and PR like I have never experienced. they hired this incredible art director — he does Madonna's stuff — and we worked together. It was brilliant: I learned so much."

Williamson's is by far the biggest collaboration H & M has undertaken with any designer. While the first "drop" is today, there will be a further high summer drop on 14 May and then a collection of menswear — williamson's first — that will go into 1,700 stores across the globe.

So, does Williamson feel famous? "No, I don't. I want to be known for what I do and I'd rather my clothes were more famous than I am."