Under the bill, headed for a D.C. Council vote next month, religious organizations would not be required to perform or make space available for same-sex weddings. But they would have to obey city laws prohibiting discrimination against gay men and lesbians.
Fearful that they could be forced, among other things, to extend employee benefits to same-sex married couples, church officials said they would have no choice but to abandon their contracts with the city.
"If the city requires this, we can't do it," Susan Gibbs, spokeswoman for the archdiocese, said Wednesday. "The city is saying in order to provide social services, you need to be secular. For us, that's really a problem."
Several D.C. Council members said the Catholic Church is trying to erode the city's long-standing laws protecting gay men and lesbians from discrimination.
The clash escalates the dispute over the same-sex marriage proposal between the council and the archdiocese, which has generally stayed out of city politics.
Catholic Charities, the church's social services arm, is one of dozens of nonprofit organizations that partner with the District. It serves 68,000 people in the city, including the one-third of Washington's homeless people who go to city-owned shelters managed by the church. City leaders said the church is not the dominant provider of any particular social service, but the church pointed out that it supplements funding for city programs with $10 million from its own coffers.
"All of those services will be adversely impacted if the exemption language remains so narrow," Jane G. Belford, chancellor of the Washington Archdiocese, wrote to the council this week.
The church's influence seems limited. In separate interviews Wednesday, council member Mary M. Cheh (D-Ward 3) referred to the church as "somewhat childish." Another council member, David A. Catania (I-At Large), said he would rather end the city's relationship with the church than give in to its demands.
"They don't represent, in my mind, an indispensable component of our social services infrastructure," said Catania, the sponsor of the same-sex marriage bill and the chairman of the Health Committee.
The standoff appears to be among the harshest between a government and a faith-based group over the rights of same-sex couples. Advocates for same-sex couples said they could not immediately think of other places where a same-sex marriage law had set off a break with a major faith-based provider of social services.
The council is expected to pass the same-sex marriage bill next month, but the measure continues to face strong opposition from a number of groups that are pushing for a referendum on the issue.
The archdiocese's statement follows a vote Tuesday by the council's Committee on Public Safety and the Judiciary to reject an amendment that would have allowed individuals, based on their religious beliefs, to decline to provide services for same-sex weddings.
"Lets say an individual caterer is a staunch Christian and someone wants him to do a cake with two grooms on top," said council member Yvette M. Alexander (D-Ward 6), the sponsor of the amendment. "Why can't they say, based on their religious beliefs, 'I can't do something like that'?"
After the vote, the archdiocese sent out a statement accusing the council of ignoring the right of religious freedom. Gibbs said Wednesday that without Alexander's amendment and other proposed changes, the measure has too narrow an exemption. She said religious groups that receive city funds would be required to give same-sex couples medical benefits, open adoptions to same-sex couples and rent a church hall to a support group for lesbian couples.
Peter Rosenstein of the Campaign for All D.C. Families accused the church of trying to "blackmail the city."
"The issue here is they are using public funds, and to allow people to discriminate with public money is unacceptable," Rosenstein said.
Rosenstein and other gay rights activists have strong support on the council. Council member Phil Mendelson (D-At Large), chairman of the judiciary committee, said the council "will not legislate based on threats."
"The problem with the individual exemption is anybody could discriminate based on their assertion of religious principle," Mendelson said. "There were many people back in the 1950s and '60s, during the civil rights era, that said separation of the races was ordained by God."
Catania, who said he has been the biggest supporter of Catholic Charities on the council, said he is baffled by the church's stance. From 2006 through 2008, Catania said, Catholic Charities received about $8.2 million in city contracts, as well as several hundred thousand dollars' worth this year through his committee.
"If they find living under our laws so oppressive that they can no longer take city resources, the city will have to find an alternative partner to step in to fill the shoes," Catania said. He also said Catholic Charities was involved in only six of the 102 city-sponsored adoptions last year.
Terry Lynch, head of the Downtown Cluster of Congregations, said he did not know of any other group in the city that was making such a threat.
"I've not seen any spillover into programming. That doesn't mean it couldn't happen if [the bill] passes," he said.
Cheh said she hopes the Catholic Church will reconsider its stance.
"Are they really going to harm people because they have a philosophical disagreement with us on one issue?" Cheh asked. "I hope, in the silver light of day, when this passes, because it will pass, they will not really act on this threat."