Raleigh, N.C. — North Carolina lawmakers and religious leaders spoke out Tuesday in support of an amendment to the state constitution defining marriage as a union of a man and woman.

Monday, Republican lawmakers filed on Senate Bill 272, "Defense of Marriage," which, if passed, would place the amendment on the November ballot as a referendum for voters to decide. House GOP leaders plan to file their version of the bill later this week.

Previous versions of the bill have failed to move forward in the Legislature. Thirty states, including all other Southern states, have passed a similar amendment.

"We are sponsoring this legislation because we firmly believe that North Carolina's marriage laws are at risk of being redefined by activist courts to include same-sex couples," Sen. Jim Forrester, R-Gaston, said.

"At any moment, a lawsuit challenging our marriage laws could be filed by a same-sex couple from our state that obtained a marriage license in a state where same-sex marriage is legal," Forrester said.

Supporters say voters have been denied the opportunity to vote, and they cite a poll by the John W. Pope Civitas Institute, a conservative public policy advocate, that shows 76 percent of those surveyed support the amendment.

Opponents say they believe the bill would violate the rights of homosexuals.

"This would go beyond just putting it in the constitution," said Ian Palmquist, director of the gay rights advocacy group Equality North Carolina. "It would actually prevent any sort of recognition, domestic partnership, health benefits through private employers and really, any sort of rights or protection for same sex couples."

"We have a gay son, and there should be equal rights for anybody, and I feel that with all my heart," said George McKee, with Parents, Families & Friends of Lesbians and Gays. "He did not choose to be gay."

Forty-one state have laws defining marriage as being between one man and one woman. Thirty states took it to voters and passed constitutional amendments.

The only time an amendment has been defeated was in Arizona in 2006, but when it hit the ballot again two years later, it passed.

Only Massachusetts and Connecticut allow gay marriage, while Vermont, New Jersey and New Hampshire allow civil unions.

Californians voted in November to overturn a court ruling that allowed gay marriage, but the state still offers domestic partnerships that guarantee the same rights as marriage.