ATHENS, Greece - In 1801, Thomas Bruce, the seventh Earl of Elgin and British ambassador to Constantinople, hit upon what he considered a splendid idea.

The ancient Greek temple of the Parthenon - among the most famous buildings in the world - was decorated with a series of 17 marble figures and a 525-foot-long frieze depicting the ancient Greek gods and heroes. They didn't seem to be doing anybody any good at the 2,500-year-old edifice atop the Acropolis.

So why not hammer them off and transport them to a place where they would be better appreciated - that is, England's green and pleasant land?

He persuaded the Ottoman Turkish rulers of Greece to allow him access to the Parthenon, where he hired a crew that chiseled and sawed off about 60 percent of the priceless marbles and sent them back to London. They eventually ended up in the British Museum.

As the 2004 Athens Olympics approaches, Greece is stepping up its demands for the return of the ancient sculptures. For 35 years, the Greeks have insisted on the marbles' return. But now the campaign is catching on internationally, starting at the grass-roots level.

"I think time will show that the public is for the return of the marbles," says Elena Korka, head of the Department for Greek and Foreign Archaeological Institutes in the Ministry of Culture. "It's becoming a universal issue. After all, the marbles were integral parts of the Parthenon, and they have meaning only when they stand next to the place of their origin."

To press its case, the ministry has been staging symposiums and photographic exhibitions on the marbles. One event was held last month at the European Parliament, which has endorsed Greece's claim. Greece is also making pleas to British officials.

The effort is catching on with the public. Committees pushing for the sculptures' return have sprung up in countries as disparate as Yugoslavia and Canada. And some of the strongest support comes from the United Kingdom, where members of Parliament and such celebrities as actors Sean Connery and Judi Dench support the British Committee for the Restitution of the Parthenon Marbles.

Former President Bill Clinton and Russian President Vladimir V. Putin have endorsed Greece's claims.

But the British Museum insists the campaign is a wasted effort. Backed by the Labor government, the museum says it won't hand over the marbles. The Greek suggestion that the marbles are meaningless out of context contradicts the philosophy of the museum, officials say.

"The great strength of the museum is that we are a universal museum," spokesman Andrew Hamilton says. "The cultures of the world are on display here in comparative context. You can see Egyptian, Roman and Greek antiquities in adjacent galleries. If you start to dismember that collection, that dimension would be lost."

The museum fears that the return of the marbles would open the floodgates of demands from former British colonies. Nigeria is seeking the return of 19th-century bronzes looted by British soldiers more than 100 years ago. And groups ranging from Native Americans to New Zealand Maoris have demanded artifacts with spiritual significance.

The Parthenon stands on the Acropolis, a mesa topped with temples in the center of Athens. In the fifth century B.C., the Athenian statesman Pericles commissioned the temple complex on the site of an earlier holy place that had been razed by Persian invaders. It was completed in 432 B.C.

Even in the early 1800s, many European intellectuals were appalled by Elgin's actions. Lord Byron, the English poet who would die in 1824 fighting for Greek independence, wrote:

"Dull is the eye that will not weep to see

Thy walls defaced, thy moldering shrines removed

By British hands, which it had best behooved

To guard those relics ne'er to be restored."

But only in the past few years has the issue gained traction with the British public, says Eleni Cubitt, secretary of the British committee supporting the return.

"We've made enormous progress," Cubitt says. "The first victory was when the British Museum stopped calling them the Elgin Marbles. [They are now called the Parthenon marbles or sculptures.] When you have a great work of art, you call it by the name of the artist who made them or the place they were found, not the person who removed them illegally."

The British Museum's board of trustees lacks the power to dispose of its antiquities, even if it were so inclined, officials insist. It would take an act of Parliament to change that. Besides, the museum argues, the sculptures are better off in London.

"The Greeks do not do anything like enough with the antiquities they have," Hamilton said. "Several pieces of frieze are still stuck up on the Acropolis, wearing away in the smog and weather."

Greece as yet has no place to house the sculptures, he says. Greece is building a new $37.7 million Acropolis museum in which it hopes to house the friezes, but it approved the plans only this spring.

In turn, Greece accuses Britain of mishandling the marbles in its possession. During a cleaning in the 1930s, the British Museum workers scoured the marbles in an attempt to bleach them in the misguided notion that the stone was originally white, rather than the honey color the rock assumes in Greece.

One sign of changing times is the number of British who are campaigning to return the marbles. In September 2000, Christopher Stockdale, a pathologist, swam 26 nautical miles from the uninhabited island of Delos, an archaeological park, to the resort island of Paros. A marathon swimmer who had crossed the English Channel and swum around Manhattan, Stockdale wanted to call attention to the marbles. He is now planning to cycle from London to Athens in a similar publicity stunt.

Reached at his office in England, Stockdale says the swim seemed to touch a chord with Greeks.

"Here was an everyman coming to Greece and highlighting the situation with a physical effort - and it was quite a physical effort - and succeeding," he says.

Greece even has offered to put aside the question of ownership for now, proposing that the British Museum lend the marbles in exchange for traveling exhibits of rare Greek antiquities to the London institution. The museum has rejected the idea. Its trustees fear that even if Greek cultural officials are well-intentioned, nationalistic politics might prevent the Greeks from following through on a promise to return the marbles to Britain.

The Greeks, in turn, are hoping that even if the ownership of the marbles isn't resolved, they will be able to display the marbles in time for the Olympics.

"It was unlawful that the marbles were removed," Korka says. "But we're not getting anywhere with that argument. So we wouldn't object to a loan."