THE NEW ESTABLISHMENT Day Four: The River Set Richard Rogers's waterside cafe is the hangout of the hip and powerful

OUR SERIES ON THE PEOPLE JOCKEYING FOR INFLUENCE IN THE LATE NINETIES

The Groucho still has its admirers, the waiting-list for the Garrick stretches into the next century, White's, Brooks, Pratts and the Arts stumble on from year to year. But clubland is not what it was. Members and staff go through the motions. But the adrenalin funk of power and influence has departed.

It has fetched up in deepest Hammersmith, at a starkly modern restaurant carved out of an old warehouse overlooking the Thames, called the River Cafe, which is owned and run by Richard (now Lord) Rogers,(right) the architect who designed the Lloyd's Building and the Pompidou Centre, and his American wife, Ruth.

Relishing the fashionable discomfort, the rich and famous troop into the steel, glass and stripped-wood ambience of the restaurant where they can pay pounds 80 per head for the cucina rustica, the elaborately simple Italian peasant cooking in which the place specialises. Lucian Freud is a regular. David Bowie, Harold Pinter, Steve Martin and the noted Garrick Club reject Jeremy Paxman, are often seen savouring the organic vegetables and the best extra virgin olive oil, and indulging the amiable bumblings of the floppy-haired boys with big chins who wait on table.

But the River Cafe is more than just another trendy restaurant. It is on the way to becoming London's most important salon and talking shop and hang-out for power-brokers as well. It could become the city's most significant modern club.

Its profile was given a sharp upward thrust in April when Tony Blair, at a public meeting on London's future, came out as a fan of modern architecture. With Britain's modernist icons, Rogers and Sir Norman Foster, on either side, Blair declared that London "needs a galvanising vision of its future. People should be able to look back at the architectural achievements of our time." When the meeting was over, it was a toss-up whether Tony and Cherie would unwind in Sir Norm's Battersea penthouse or a little further west at Roger and Ruthie's. Roger and Ruthie won the day.

What fresh-faced young moderniser could turn such an invitation down? It's not just the glittering guest list, the Yentobs and Serotas and Jaggers and Geldofs, which give it a special appeal. It's the presence of Rogers himself, for whose architectural office the restaurant functions as staff canteen (they get a discount). This intensely political figure, a grimacing, mumbling, rock-faced dyslexic, 18 going on 65 in appearance, who dresses like an early Sixties jazz fan (red socks with everything), has, by his vigorous, relentless campaigning, made the governance of London and the revival of the Thames into burning political issues.

Without necessarily willing it, Lord and Lady Rogers (as their friends will be expressly forbidden to describe them) have reinvented the London club for the late Nineties. The charm of the clubs of St James's is a tissue of ambiguities: grandeur and shabbiness, dignity and intimacy, strictly observed table manners but nursery food. Members go there to swank it up, but part of the treat is that once inside you can behave as you would at home, or worse. Slump in an armchair with the paper. Get soggily drunk without exciting comment. Toss your watch to the man on the door and tell him to wind it, there's a good chap.

River Cafe plays similar games with expectation and propriety. It's notoriously expensive but disarmingly laid-back. The food has been praised to the skies, but you can never be sure what you're going to get, because, as Ruth Rogers said recently, "We change the menu twice a day by looking in the fridge and seeing what's there." Richard Rogers is a passionate enemy of the motor car, but it's almost impossible to get there any other way. When you arrive, there's nowhere to park - but the hairy guy in the Dracula cloak at the door will park it for you, which gives you the illusion you've been transported to Los Angeles, car capital of the world.

The edge the River Cafe has on any other such gathering place is that it is animated by ideas, electric with Rogers's prowling, lupine presence as he moves from table to table, pouncing on the rich and influential. In the New Yorker in July, Adam Gopnik described the cafe's dominant notion as the "century-old William Morris-to-Reyner Banham sensibility, which insists that faith in common sense, clean lines, English river air and imported Mediterranean folk culture will make England young again."

This may seem a rarefied proposition for a party reared on the dripping sandwiches of Labourism. But it's intoxicating, it's hip, and the new establishment is knocking it back.

Tomorrow: media types