TOKYO -- What would happen if Congress got so fed up with housing prices in the Washington area and daily backups on the Capital Beltway that it voted to move the federal government lock, stock and pork barrel to a secluded glen in the hills of West Virginia?

Contemplate that notion and you'll begin to understand the shock Tokyo residents are feeling now that Japan's Diet, the national parliament, has passed a resolution saying that it should move to a new home outside this pricey, polluted and vastly overcrowded sardine can of a city.

The resolution, backed by advocates of a national movement called New Capital, won surprisingly strong approval last month in both houses of the Diet. More important, it has won support from Shin Kanemaru, a 76-year-old titan of the dominant Liberal Democratic Party who has built up such a wide network of contacts that he is widely recognized as the most powerful politician in Japan.

"Of course, everybody says it can never happen," said Wakako Hiranaka, a tenacious, Brandeis-educated Diet member who is a leader of the New Capital drive. "But Mr. Kanemaru gets things done, and he wants a new national capital to be part of his political legacy."

Viewed in American terms, Tokyo is New York, Boston, Los Angeles and Washington combined -- the financial, cultural, academic, media and government center of the nation. In a society in which almost everything is done through networks of personal connections, Tokyo is the network par excellence.

The reasons Kanemaru and a plethora of other politicians want to move part of this power network somewhere else stem from the difficulties of living in and managing one of the most populous metropolitan centers on earth. The vast range of urban troubles is known here generically as "the Tokyo Problem."

At least 30 million people live within a 30-mile radius of downtown Tokyo -- more than 10 times the number within the Washington beltway, a slightly smaller area. The population sprawl is so great that Yokohama, a suburb about 20 miles from downtown, has passed Osaka to become Japan's second-largest city.

The metropolitan area has simply run out of room for people, their cars and their trash. Housing is so scarce that single people routinely live in apartments no bigger than a walk-in closet in an average American home. On morning radio, a rush-hour traffic jam stretching a half-dozen miles is called "moderate." When Tokyo police surveyed parked cars one day last spring, they found not 30 percent, not 60 percent, but 90 percent of them parked illegally.

Many workers must live so far from downtown that a 90-minute commute on a train so crowded nobody can move a limb is considered normal. And if getting into Tokyo is tough, getting out can be even tougher. For this New Year's holiday, every seat on every train leaving Tokyo was snapped up within two hours after tickets went on sale.

In short, "The Tokyo Problem" is a chief cause of the central irony of modern Japan -- as the country has grown rich, the standard of living for tens of millions remains at a level that would be unacceptable in other developed countries. Still, more and more people pour into Tokyo every year, drawn by the irresistable glamour and excitement, the bright lights and brilliant scholars, and the seemingly inexhaustable supply of jobs.

"Tokyo is everything," said Hiranaka. "The power is here. The money. The culture. If we're ever going to deal with the Tokyo problem, this incredible power concentration must be broken. Well, we knew we would never get businesses or banks or the media to move out of Tokyo. So we decided the way to do it is to move the Diet, and the rest will follow."

The Diet resolution does not have the force of law, and nobody here is packing yet. But there is a growing sense that a new capital, in some rural area an hour or so from Tokyo, might come into being.

Japan has been moving its capital around for centuries. Tokyo didn't get the honor until 1869, when the fortress town of Edo was renamed "Eastern Capital" -- two words rendered to and kyo in Japanese characters.

The idea of moving the current government out of Tokyo has been entertained before. In 1988, the prime minister ordered 80 federal agencies to leave the city. After three years of dillying and dallying, 76 of them are still here.

That is why the New Capital movement has now focused on the narrower goal of moving the Diet. "The basic idea is that most Diet members have their homes somewhere else, so we're not so attached to Tokyo," Hiranaka said. "We can see the need for some part of the government to move out, and the Diet is probably the easiest target."

To make their idea more attractive, Hiranaka, Kanemaru and other New Capital advocates note numerous advantages to building a new home for the Diet. A new community for parliament, its staff and the lobbying community would spark a construction boom; that, in turn, would be a boon to politicians, because the construction industry is a key source of political contributions here. In addition, the project would help mollify U.S. trade negotiators, who are demanding that Japan spend billions of dollars on the country's infrastructure.

Moreover, a new Diet building outside Tokyo would satisfy members miffed by Tokyo Mayor Shunichi Suzuki's decision to build a lavish new town hall a few miles from the stodgy 70-year-old concrete monolith that houses the Diet. The billion-dollar town hall, a twin-turreted urban castle that will be the tallest building in Japan when it is completed, towers over the Diet building in height and style.

Many political experts here scoff at the idea that the Diet might leave Tokyo. "Maybe they could move the building out somewhere," said Shigezo Hayasaka, a well-known political analyst, "but the actual work, the staff -- it's unthinkable that it would not be in Tokyo."

But if anybody can achieve the unthinkable in today's Japan, it is the powerful elder statesman, Kanemaru. "The Diet should be a model," he said recently. "Within 20 years, it should no longer be in Tokyo."