BRASÍLIA, May 10 — Gay activists kicked off an intensive campaign today to persuade Brazil's Congress to legalize same-sex unions, despite opposition from outspoken evangelical Christian deputies and Brazil's vast Roman Catholic majority.
A vote on the bill had been due on Wednesday but it was rescheduled for May 16, because the lower house had not taken it up by the end of the day.
Gay advocates were happy to gain time, they said, because they continue to see resistance to the measure that would allow gay people to transfer property and extend Social Security benefits and health plans to their companions.
"This is going to be a week of lobbying," the president of the Gay Pride Parade Association, Beto de Jesus, said. "We have a list of deputies who do not have a clear position and we are going to work on them."
If the bill is approved, Brazil would be the first country in Latin America to allow same-sex unions, as France and Australia do. The Netherlands, however, has legalized actual gay marriages.
In the United States, only Vermont recognizes same-sex unions.
Although advocates for rights of gay people combed the halls of Congress to drum up support for the bill, evangelical legislators threatened to retaliate against members of Congress who voted for the bill.
"The council wants to make public what these people are doing, promoting exactly the opposite of what God intended," said Deputy Amarildo Martins, who is evangelical. He said they would go to the pulpit to denounce supporters of the bill.
Mr. Martins belongs to the evangelical church, a branch of the Protestant movement that has spread rapidly in Brazil with televised services that particularly reach out to the poor.
The bill was introduced in 1995 but has been modified to allow the extension of benefits to any kind of same- sex "partner" such as from brother to brother or granddaughter to grandmother to try to ease opposition in a country that has more Roman Catholics than any other in the world.
The prospects for passing the measure are not assured, especially because of religious opposition and because Congress is mired in investigations into allegations of corruption.
"The rule that all are equal" under the Constitution, Mr. Martins said, "is only valid when it doesn't interfere with the higher law, which is that of God."