CONSIDERING that he has his share of angst-ridden moments, the photograph hanging outside Marc Jacobs’s Paris office, featuring him dressed as mid-period Barbra Streisand, presents certain problems to those who tend to think of him as Slightly Tortured. His PR, Camille Miceli, the kind of Parisian who wears white Bermudas in April and makes you feel hopelessly provincial for not thinking of it first, helpfully points out the identities of the other “Streisand” portraits next to her boss’s — all members of Jacobs’s long-serving team at Louis Vuitton. If nothing else, they are a testament to the camaraderie he inspires among his team.

Unlike some of his peer group, Jacobs is not famous for dressing up in drag. He is famous — lest it needs repeating — for being one of the world’s most influential designers. Two days after this interview in Paris, the brand director of a well-known British high-street chain told me that Jacobs is his god; indeed, without Jacobs, there wouldn’t be much of a chain. Less austere than Prada, cooler than Dior or Gucci, he has done more for the British (and every other) high street than Marks & Spencer, Zara and Topshop put together, though as far as any one knows he hasn’t been paid directly for any of it.

Primarily he is a very upscale designer. So expensive is Jacobs — his own label is produced in New York — and so rarefied the clothes that he introduced to Louis Vuitton, the luxury accessories brand which he rescued from duty-free hell six years ago (although lusted after the world over, Jacobs’s ready-to-wear collection reaches only a few of the brand’s stores), that he’s been accused of addressing himself to a tiny clique band of fashion insiders. Wrong.

For the best part of a decade, Jacobs has known exactly what millions of women, from pampered Manhattan fashion editors to secretaries in Manchester, want to wear just before they want to wear it. This isn’t intellectual fashion; it’s far more meaningful. It taps into that part of the Zeitgeist with which we can most intimately share. Bags with big zips and a confusing number of pockets, pointy little mouse shoes, military jackets with puff shoulders and frogging, long scarves with pea coats, ironed jeans with couture-sharp creases, cropped trousers, shiny big plastic buttons — in short, an aesthetic that sums up the downbeat glamour that is what beatnik style was to the 1950s — it all comes from the Marc Jacobs, Louis Vuitton or Marc by Marc Jacobs collections. Or, more likely, from high street lines inspired by them. More than any one else Jacobs is responsible for the ultimate symbol of satiated capitalism — the waiting list for luxury items that no one actually needs. The good — or bad — news is that those waiting lists are about to multiply.

There’s a rumour that Louis Vuitton, which now turns over around $3 billion (£1.8 billion) a year, according to one Goldman Sachs analyst (when Jacobs arrived in 1997, turnover was $1.98 billion), wants him to produce more bags, more often (an ironic twist for a notorious perfectionist). “That may be true,” he says sounding surprisingly serene, before picking up a pair of scissors and spearing a folded-up piece of paper with them, a tic that contradicts his studiously controlled voice. “At least I think that’s the intention, from what I understand.”

Jacobs is sitting in the large corner office that he occupies in the Louis Vuitton headquarters, on the Pont-Neuf — a building that’s all Art Nouveau curlicues on the outside, soaring 1990s café crème marble on the inside — his back outlined against the cupolas of La Samaritaine, the department store across the street. Pictures of Kate Moss (his favourite model) flap on his pinboard. Decades of crimson-bound issues of Vogue are piled on the window sills (Jacobs bought the collection from the late Liz Tilberis, one-time editor of Harper’s Bazaar and British Vogue).

He’s in his usual uniform of charcoal T-shirt, Converse sneakers and jeans — the school of international urchin, with a soupçon of Weltschmerz. His ponytail has been sacrificed for a Beatles mop that makes him seem younger than the average partied-out 40-year-old and slimmer than he’s looked recently. These days he says he’s not interested in partying or drinking. He prefers to visit art galleries or walk his bulldog Alfred in the Jardin du Luxembourg.

If communications between Jacobs and his employers at LV seem sketchy (vis-à-vis the bag policy), he says happily that that’s the way it has always been. There was a painful, lengthy gestation period between the hype that greeted his move to LV in 1997 and the first collection, accompanied by the inevitable rumours that Jacobs, easily capable of debating the length of a sleeve for days, weeks even, might be out before he had even started.

“In the beginning I didn’t know if it was better to give people what they wanted or what I thought they wanted. I didn’t know what was required. No one told me; in fairness, I never asked. Louis Vuitton had never done clothes before. It was a clean slate. I thought I ought to be able to figure it out myself.” He stabs the paper.

An agonised, existential experience, in the grand French tradition then?

“Exactly, I made it as painful as possible for myself and the rest of the team.” Snip!

The first item he produced for the house that had made its name, literally, plastering monograms over anything that stood still long enough to be stamped, was a white kid bag with no logo. “It was possibly the antithesis of everything the label stood for,” he laughs ruefully. “It was not successful.”

This was followed by his first range of clothes for the house, a minimalist collection in excruciatingly expensive cashmere (and edgy nylon) that was big on luxurious details such as 24in hems and short on gilt buttons and other favoured Gallic status symbols. The French were not crazy about that either.