"There would be no need for this bill if there was the right for gays and lesbians to marry," said Roger Coggan, director of legal services for the LA Gay & Lesbian Center.

Alarmed business groups and religious conservatives have launched an aggressive campaign against the measure, saying the consequences could be higher costs and fewer services for the needy.

"They are trying to force their own agenda on any business doing business with the state," said Karen Holgate, a policy analyst for the conservative Capitol Resource Institute.

Carried by San Diego Assemblywoman Christine Kehoe, AB 1080 would require vendors and contractors to offer domestic partners the same health and retirement benefits as those provided to married couples.

Under a 1999 state law, couples can register as domestic partners if they have lived together for an extended period. However, a year later, California voters approved an initiative that bars same-sex couples from marrying.

But the bill could affect "tens of thousands" of contractors and vendors who sell the state $7 billion worth of everything from office computers to inmate meals every year, according to Ken Hunt, a spokesman for the Department of General Services.

Kehoe is trying to carve out a special provision for religious organizations that provide services.

The influential California Chamber of Commerce has weighed in, contending the legislation would limit the number of bidders for state contracts and potentially force taxpayers to pay more for goods and services.

"It violates our core principle that state contracts should be for the best possible product for the lowest price," said Dominic DiMare, a chamber lobbyist.

Kehoe, though, said that argument is overblown. The state regularly receives many bids for goods and services even though it imposes nondiscrimination orders and other requirements on contractors and vendors. Valuable employees will gravitate toward firms that offer equal benefits, she added.

San Francisco, the city of Los Angeles and San Mateo County have imposed similar requirements. The city of San Diego offers domestic partner benefits, but does not make it a condition of contracts, according to Kehoe.

Kehoe said she has become concerned about reports of same-sex couples left in a fiscal lurch after an uninsured partner became ill.

"The couple has no recourse. They have no way of helping their life partner," Kehoe said.

Democratic Governor Gray Davis has sent hints through intermediaries that he would prefer to keep the issue on hold until after November, she said.

"We need to assess the strengths of the bill and how much further we can take it," Kehoe said. "It may be that the timing is not absolutely optimal, but the best way to test that premise is to push and see how far we get."