AUGUSTA, Maine — Supporters of traditional marriage will gather from 6 to 8 p.m. today at the Augusta Civic Center to voice their opposition to a bill that would allow same-sex couples to marry in Maine.

Representatives of the Maine Family Policy Council, formerly the Christian Civic League of Maine, the Maine Jeremiah Project, Concerned Women for America of Maine and the Roman Catholic Diocese of Portland are expected to participate in the “Stand for Marriage Rally.”

Tony Perkins, president of the Washington, D.C.-based Christian Family Resource Council since 2003, is scheduled to give the keynote address. Perkins, 45, served in the Louisiana House of Representatives before taking his current position. The council is an offshoot of James Dobson’s Focus on the Family, based in Colorado Springs, Colo.

Organizers have said that hundreds are expected to attend the event. This is the first statewide event that all groups opposing same-sex marriage have held together since it was announced that a bill to legalize same-sex marriage would be introduced this legislative session.

A small group of clergy that support the bill are expected to stage a counter rally Sunday at the Augusta Civic Center.

“The definition of marriage as the union of one man and one woman is rooted in the order of nature itself,” Perkins wrote in a column published in 2006 after the Massachusetts Supreme Court in essence legalized same-sex marriage in that state. “It promotes the continuation of the human race and the cooperation of a mother and a father in raising the children they produce.”

“This union,” he continued, “can only be protected through amending the U.S. Constitution. If it’s not, activists will continue using the courts to sell a five-legged dog. But as we say where I’m from in Louisiana, ‘That dog won’t hunt.’”

Same-sex marriage supporters have chosen to go to the Legislature rather than the courts.

Rep. Dennis S. Damon, D-Trenton, said at a press conference in the State House that he would sponsor the bill. The proposed legislation also would repeal the Defense of Marriage Act that defines marriage as a union between a man and a woman.

A competing bill that would extend to couples on Maine’s Domestic Partner Registry the same legal rights and benefits as married couples was introduced by Rep. Leslie Fossel, R-Alna. It is not intended to create civil unions.

Neither bill has been printed but both are expected to be referred to the Judiciary Committee.

Supporters of traditional marriage had expected to submit a bill that would create an amendment to the state constitution that would define marriage as between a man and a woman. They did not find a legislator to sponsor the measure before the deadline to submit bills.

If same-sex marriage were to become law, opponents have said they would launch a People’s Veto effort and ask voters to repeal it.

Proponents of same-sex marriage on Thursday delivered Valentines to legislators that included copies of the video, “The Way Life Should Be: Marriage in Maine.” The Freedom to Marry Coalition that is made up of 22 groups including Equality Maine and the Maine Civil Liberties Union sponsored the event called “We Are the Heart of Marriage in Maine.”

Over the next few weeks, Equality Maine plans to sponsor house parties in Penobscot County and other communities to talk with voters about the bill and why same-sex couples should be able to marry, Shenna Bellows, executive director of the MCLU, said Sunday.