San Francisco may be the only place in the world where a confrontation between church and state could be sparked by a band of bearded transvestite nuns.
That is exactly what has happened as the "Sisters of Perpetual Indulgence" a troupe of wimplewearing performance artists, has pushed the city's liberal government into a collision course with the Catholic Church.
The sisters, an irreverent group of gay artists, AIDS activists and assorted extroverts, have alternately offended and amused San Francisco for 20 years, appearing in parades and at charity events sporting beards, false eyelashes, face paint and full nun's habits.
Zooming around on roller skates and specialising in the raunchy and the profane, the sisters have become a minor San Francisco tradition - beloved by some, belittled by others and unnoticed by most.
But they stirred a hornet's nest among politically powerful Catholics when they announced plans to mark the group's 20th anniversary by closing a city street for a block party on Easter Sunday. The spokesman for the Archdiocese of San Francisco, Mr Maurice Healy, condemned the plan as a deliberate insult to the church and demanded that the city rescind its approval for the party.
The Catholic League for Religious and Civil Rights, meanwhile, issued an ultimatum to Mayor Willie Brown and the city Board of Supervisors calling on Catholic groups to boycott San Francisco unless the sisters are forced to reschedule their party.
"Many people think that San Francisco is the city of tolerance. But is a lie - an outrageous lie," the league president, Mr William Donohue, said in a half-page advertisement in the San Francisco Chronicle. "Our objection to the `sisters' does not centre on men dressing as nuns: it centres on their obscene assaults on the Eucharist, the very nucleus of Catholicism. That is why we are outraged," the advertisement said.
The sisters and their supporters have reacted equally strongly to the attack, declaring that they will never give up their habits just to please orthodox Catholics.
"Regardless of what the board decides, we are still having our party," Sister Ann R. Key said. "This whole thing is really shaping up as a very strong Catholic attack on the gay community, not just queer sisters."
The Board of Supervisors President, Mr Tom Ammiano, an openly gay former professional comedian, quickly made it clear he did not support forcing the sisters to bend to Catholic demands.
"Changing the date is a scam," Mr Ammiano said. "It's an empty gesture to appease inappropriate pressure on the democratic process. I'm very concerned about the very cherished value of separation of church and state."
Mr Brown, caught in a cross-fire between two of the city's most powerful voting blocks, has wavered, appearing to favour the party at first, then gently suggesting that perhaps it would be better to reschedule it. "Obviously we support the idea of free speech and freedom of expression but there are limits and limitations that clearly must be imposed," he said.