TRENTON - Five moderate Republican state senators who have been under pressure to support gay marriage said yesterday that they would not vote for a bill allowing same-sex couples to wed in New Jersey.

Instead, they favor strengthening and enforcing the state's civil-union law, which they said gives gay and lesbian couples the benefits of marriage without the title.

Advocates for same-sex marriage say civil unions confer a status that is separate and not equal. Opponents say the Legislature should not alter the traditional definition of marriage.

"I really appreciate their recognition that civil unions are not working and do not provide equal protection under the law," said Sen. Raymond Lesniak (D., Union), a cosponsor of the gay marriage bill. "I think we can convince these well-intentioned senators that separate can never be equal."

The Republican senators - Jennifer Beck of Monmouth County, Andrew Ciesla of Ocean County, Christopher "Kip" Bateman of Somerset County, Sean Kean of Monmouth County, and Thomas H. Kean Jr. of Union County - said the bill was unlikely to pass, but gay-rights activists vowed to fight on.

"I don't see a single new development in the [Republicans'] statement," said Steven Goldstein, chairman of Garden State Equality, New Jersey's main gay rights group.

A vote on the bill was put off in the Senate this month when it appeared unlikely to pass. Senate sponsors hastily shifted strategy, deciding to try their luck in the Assembly rather than have the bill go down in defeat. The Assembly had been waiting for the Senate to act before taking up the legislation.

Assembly Speaker Joseph J. Roberts Jr. (D., Camden) has not decided whether to post the bill for debate. He said his decision hinges on whether there is enough support for it to pass.

"The best way to fix the ineffective civil-union law isn't by tinkering with it and maintaining a separate-but-equal standard," Roberts said yesterday. "Having said that, I continue to discuss this issue with our caucus to gauge whether there is enough support for it."

Proponents are under a tight deadline to get the bill through the Legislature while there is still a governor in office who will sign it. Gov.-elect Christopher J. Christie, who takes office Jan. 19, has said he would veto gay marriage legislation.

Opponents of gay marriage said voters should decide the issue.

Four states - Connecticut, Iowa, Massachusetts and Vermont - allow gay couples to marry. A gay marriage law in New Hampshire goes into effect Jan. 1.

After suffering a series of setbacks in California, New York and Maine, gay marriage supporters got a victory Tuesday when the Washington City Council legalized same-sex marriage in the District of Columbia. Gay couples there could begin marrying as early as March.

Associated Press writer Geoff Mulvihill contributed to this report.