ATHENS, Greece — After all these centuries, Zeus may have a few thunderbolts left. A tiny group of worshippers plans a rare ceremony tomorrow 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 that 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 tomorrow's 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 Greek gods, was founded last year and won a court battle for official state recognition.

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-nationalists 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. About 97 percent of native-born Greeks are baptized Orthodox Christian, and the church regards ancient religious practices as pagan. Representatives of the church in the past have not attended flame ceremonies at Olympia because reference is made to Apollo, the ancient god of music and light.

Christianity took hold in Greece in the 4th century, after Roman Emperor Constantine's conversion. Emperor Theodosius wiped out the remaining vestiges of the Olympian gods when he abolished the Olympic Games in 394 A.D. The modern revival of the Olympiad maintains a slender link to ancient ceremonies.

"Christianity did not prevail without bloodshed," said Peppa, a novelist and historical writer. "After 16 centuries of negativity toward us, we've gotten something in our favor."

Ellinais is demanding that the government allow it to register its downtown offices as a place of worship — a move that could allow the group to perform weddings and other ceremonies. They threaten further court action unless that is granted.