Fifty-four percent of New Jersey voters said same-sex couples should be allowed to wed. By about the same margin, voters also thought the issue should be placed on a ballot, according to a survey by the Eagleton Center for Public Interest Polling at Rutgers University.

New Jersey's Democratic leadership, which controls both houses of the legislature, has made gay marriage a top priority this session, saying the state's civil union law does not adequately protect same-sex couples.

The state Senate approved a bill to authorize same-sex marriage 24 to 16 on Monday, and the measure was expected to be approved by New Jersey's lower house when it votes on the issue on Thursday.

But Christie, one of the country's leading Republicans and a possible vice presidential candidate, has vowed to veto the bill if it comes to his desk. Democrats do not appear to have enough votes to override a veto.

Christie has suggested the bill's supporters put the issue directly to voters, and has even suggested the measure could pass, given the support for same-sex marriage revealed by recent polls.

Christie went on to say that activists in the civil rights era "would have been happy to have a referendum," a statement that angered many. He later apologized.

According to the poll, four in 10 voters agreed with the state's Democratic leadership, which has maintained that civil rights issues should never be put to a popular vote.

"Subjecting the equal rights of same-sex couples to the whims of the majority - and to the multimillion-dollar campaign which will inevitably precede the vote from special interests nationwide, intent on preserving the status quo -- to me, that's offensive and unprecedented," Senate Majority Leader Loretta Weinberg, a Democrat, said on Monday, before casting her vote in favor of the same-sex marriage bill.

Weinberg noted that in 1915, New Jersey voters rejected women's sufferage by a 2-to-1 margin. Five years later, women won the right to vote with the passage of an amendment to the U.S. Constitution that was approved by Congress and ratified by state legislatures.

The survey of 914 adults was conducted from February 9 through February 11, and had a margin of error of plus or minus 3.3 percentage points.

Gay marriage is already allowed in New York, Connecticut, Iowa, Massachusetts, New Hampshire and Vermont plus the District of Columbia. On Monday, Washington state Governor Christine Gregoire signed a bill to make Washington the seventh state to legalize same-sex marriage.

A lawsuit that challenges New Jersey's civil union law is pending.

(Reporting By Edith Honan; Editing by Cynthia Johnston and Eric Beech)