WASHINGTON (AP) _ More and more of this city's power brokers seem to be skipping those three- martini lunches in favor of late-afternoon English tea, closing their deals over a cup of Darjeeling, watercress sandwiches and crumpets slathered with strawberry jam.

Some of Washington's most exclusive hotels report that corporate executives, lawyers, lobbyists and even congressmen are leading a briefcase invasion of the genteel sanctuaries once reserved for white-gloved ladies in their search for a quiet place to wheel and deal.

''What's happening is that teatime is replacing the cocktail hour,'' says trial lawyer Cary Pollak, a self-taught expert on afternoon tea. ''Instead of the power lunch, it is getting to be more the custom to conduct business over a power tea.''

Georgetown's swank Four Seasons Hotel, part of a Canadian chain of hostelries, is credited with introducing the capital to the leisurely delights of afternoon tea about 10 years ago. Other hotels followed, trundling out their tea carts every day at 3 o'clock.

Most of the hotel restaurant managers interviewed in a random telephone survey said their tea customers at first were almost exclusively women, but they are seeing more and more men enjoying this hallowed, high-calorie English ritual.

''I think it's catching on,'' said Cynthia Gumnick, manager of the 50-seat Nest Lounge in the Willard Intercontinental Hotel, two blocks from the White House.

''We're seeing more and more men,'' she said. ''They don't turn up their noses at the door like they used to. They come in, sit down and enjoy themselves. Sometimes four or five gentlemen will order a larger table and spread out their papers before they order tea.''

Prices generally range from about $7 to $12, depending on what customers consume with their tea.

The Willard's typically lavish spread includes a choice of eight varieties of hot tea, followed by finger sandwiches, scones with thick Devon cream and strawberry jam and an assortment of cakes, fruit tarts and petite pastries.

Will Hancock of the Four Seasons reported that a couple of big-name congressmen, whom he refused to identify, have gotten into the habit of slipping into his Garden Terrace restaurant occasionally to confer over afternoon tea.

David Carr, manager of the lobby lounge at the Park Hyatt Hotel, said a growing number of men accounts for about 20 percent of his teatime business. He hopes to boost that figure with a marketing campaign promoting afternoon tea as ''a good opportunity to relax and conduct business.''

Steve Johnson of the Mayflower Hotel said the growth in male customers for afternoon tea coincides with a general decline in alcoholic consumption and the lure of a quiet, relaxed cafe atmosphere where the hubbub of the cocktail bar never intrudes on serious conversation.

All this is pleasant news to Pollak, 44, a civil trial lawyer for the District of Columbia and bachelor chef who gives cooking classes for interested amateurs in the country-style kitchen of his townhouse in suburban Alexandria, Va.

''Afternoon tea is one of the finest customs we have inherited from our English ancestors,'' said Pollak, who instructs his students on the formal etiquette and proper preparation of an English tea, which he frequently serves to his weekend dinner guests.

Pollak shows his students how to cut a lemon in thin slices for resting in the bottom of teacups. They learn to carve the crusts from tiny watercress and cucumber sandwiches. They roll the dough on his antique oak kitchen table to make scones, the biscuit-shaped cake that traditionally is served with a dollop of clotted sweet cream.

''Litigation is very adversarial and aggressive,'' says Pollak, who comes home exhausted from his 60-hour work weeks. ''Teaching people how to prepare a gourmet meal or an afternoon tea gives me pleasure. It's not a battleground, and everybody wins.''