ATHENS, Greece — After all these centuries, Zeus may have a few thunderbolts left. A tiny group of worshippers plans a rare ceremony today to honor the ancient Greek gods, at Athens' 1,800-year-old Temple of Olympian Zeus.

Greece's Culture Ministry has declared the central Athens site off-limits, but worshippers say they will defy the decision.

"These are our temples and they should be used by followers of our religion," said Doreta Peppa, head of the Athens-based Ellinais, a group campaigning to revive the ancient religion.

"Of course we will go ahead with the event ... we will enter the site legally," said Peppa, who calls herself a high priestess of the revived faith. "We will issue a call for peace; who can be opposed to that?"

Peppa said the ceremony will be held in honor of Zeus, king of the ancient gods, but did not give other details. The daily Ethnos newspaper, citing the group's application to the Culture Ministry to use the site, said the 90-minute event would include hymns, dancers, torchbearers and worshippers in ancient costumes.

Greece's archaic religion is believed to have several hundred official followers, mainly middle-aged and elderly academics, lawyers and other professionals. They typically share a keen interest in ancient history and a dislike for the Greek Orthodox Church.

Ancient rituals are re-enacted every two years at Olympia, in southern Greece, where the flame lighting ceremony is held for the summer and winter Olympic games. But the event is not regarded as a religious ceremony and actresses are used to pose as high priestesses.

Last year, the Culture Ministry, fearing damage to monuments, blocked an initiative to hold an international track meet at Olympia. A panel of ministry experts ruled against Sunday's ancient ceremony at the ruins of the Temple of Zeus on similar grounds.

"Ancient sites are not available for this kind of event," ministry official Eliza Kyrtsoglou said. It was not clear whether the government had plans to block the worshippers.

Peppa's group, dedicated to reviving worship of the 12 ancient gods, was founded last year and won a court battle for official state recognition of the ancient Greek religion.

Those who seek to revive the ancient Greek religion are split into rival organizations which trade insults over the Internet. Peppa's group is at odds with ultra-national- ists who view a revival as a way to protect Greek identity from foreign influences.

They can't even agree on a name for the religion: One camp calls it Ancient-Religion, another Hellenic Religion.

The worshippers also face another obstacle: Greece's powerful Orthodox Church.