ATHENS, Greece (AP) — After more than a century of fruitless lobbying, Greece is now pinning its hopes of reclaiming the 5th-century B.C. Parthenon Sculptures from Britain on a mediation effort backed by the U.N. cultural agency.

Culture Minister Costas Tassoulas said Wednesday UNESCO has urged Britain to consider a year-old mediation proposal to resolve the world’s most famous heritage dispute.

The marble sculptures were removed to Britain — illegally, according to Greece — from the Parthenon temple on the Acropolis in the early 19th century.

The British Museum, where they are displayed, and the British government say the works are better off in London.

London lawyers, including U.S. actor George Clooney’s wife, Amal, advising Greece said Athens could take the issue to an international court, if mediation fails.

Tassoulas played down that option.