Warning of divine retribution and possible violent protest, evangelical Christians and rabbis from the United States have joined forces with ultra-Orthodox Jews in Israel to fight plans to hold an international gay festival in Jerusalem this summer.

The WorldPride Parade (search), last held in Rome in 2000, is a 10-day event including street parties, workshops and a gay film festival. Jerusalem's ultra-Orthodox Jewish mayor, Uri Lupolianski, says he is powerless to interfere, as public events are licensed by the police, not City Hall.

At a news conference Wednesday, California pastor Leo Giovinetti (search) said hosting the 10-day World Pride event could bring divine retribution upon Jerusalem, citing the biblical story of Sodom and Gomorra as a precedent.

Ultra-Orthodox Israeli lawmaker Nissim Zeev (search) hinted at more earthly troubles. "With demonstrations we never know how they end up," he said. "Residents here are enraged. Everything should be done to stop this (event) and not cause people to break the law."

Lupolianski also sees a potential threat to public order in a city where religious feelings run high. His office warned in a statement that the parade "might instigate clashes."

In the past, Israeli gays have held small marches in Jerusalem that have passed relatively peacefully, with a few shouted insults from onlookers and minor acts of vandalism.

This time the plan is for a major international happening; the Rome event attracted tens of thousands of participants.

Organizers of the festival, under the theme "Love Without Borders" say they want to promote coexistence.

"The holiness of Jerusalem does not come from manipulating religion to keep people away," said Hagai El-Ad, the director of Open House, the Jerusalem group that has organized local gay parades in the city. "Jerusalem's holiness comes from it being a city that can bring together all kinds of people."

Giovinetti, from San Diego, has a nationwide radio ministry in the United States that he says reaches millions. He is seeking a million signatures for a petition against the August festival, which he said debases the sanctity of Jerusalem.

All 11 lawmakers from Zeev's Shas party have pledged to sign the petition. Benny Eilon of the right-wing National Union says he has promises of support from another 30 members of the Israeli parliament, including Muslim cleric Abdulmalik Dehamshe.

Giovinetti said that as a devout Christian, he felt bound to join with observant Jews to fight an offense to their shared traditions.

"I haven't come because I have hate for the homosexuals, I've come because I have love for the Jews," he said. "I believe that this march has been brought upon our Holy Land and that we're defending ourselves, not the aggressors."

A majority of Jerusalem's more than 600,000 residents are either Orthodox Jews or Muslim or Christian Palestinians, traditional communities that oppose homosexuality.

New York Rabbi Yehuda Levin, representing the Rabbinical Alliance of America — a group of 700 Orthodox rabbis — said that throughout the world many traditional Jews are offended by the planned event.

"This is not a parade. A parade takes a few hours. This is a 10-day homosexual convention with many outdoor activities and a 10-day pornographic film festival," he said.