BOSTON (Reuters) - A Maine lawmaker introduced a bill on Tuesday to legalize same-sex marriage, but it looks set to face tough opposition and bring a rancorous fight over the definition of marriage to the rugged eastern state.

Demonstrators wave flags in support of gay marriage in front of the Massachusetts State House in Boston, Massachusetts, July 12, 2006. REUTERS/Jessica Rinaldi

The legislation proposed by Democratic state Sen. Dennis Damonck would make the state the nation’s third to allow same-sex marriage. It seeks to redefine marriage as the legal union of two people rather than between a man and a women.

“Today I have submitted an act to end discrimination in civil marriage and to affirm religious freedom,” he told a news conference in the state capital Augusta.

As he spoke, Republican Rep. John Tardy was drafting legislation to enshrine the definition of marriage as one man and one woman into the state constitution. “The language is being worked on now,” his spokesman said.

The looming fight in Maine, a rural state of 1.3 million people with a Democratic-controlled legislature, underlines a concerted push for same-sex marriage recognition in New England’s six states by gay and lesbian advocates -- a bid that would effectively create a regional niche for gay marriage.

In November, Connecticut became the second U.S. state to allow legal same-sex weddings after Massachusetts’ top court ruled in 2003 that a ban on gay marriage was unconstitutional, paving the way for same-sex marriages the following year.

On Friday, New Hampshire Rep. Jim Splaine signed off on legislation proposing same-sex marriage in that state, which borders both Maine and Massachusetts. He said he expected the bill to come up for a public hearing in two or three weeks.

Five of New England’s six states already offer same-sex couples some form of legal recognition, with New Hampshire and Vermont permitting same-sex civil unions that grant many of the same rights as married couples but lack the full legal protections of marriage.

“I think it is important to make our civil unions have full marriage equality with the word ‘marriage’ so that it is clear that we do not discriminate and that we welcome same-gendered couples,” Splaine told Reuters in an interview.

Gay & Lesbian Advocates & Defenders, a group of lawyers who led the legal fight for same-sex marriage in Massachusetts and Connecticut, said on Tuesday similar legislation was being drafted in Rhode Island and Vermont.

The group has set a target of bringing same-sex marriage to all six New England states by 2012.

Some economists say carving out an economic niche for gay and lesbian weddings -- and the spending that comes with them -- makes sense at a time same-sex marriage has stalled in California and a recession is deepening.

M.V. Lee Badgett, an economist at the University of Massachusetts’ Institute for Gay and Lesbian Strategic Studies, led a study released in July that said over the next three years about 32,200 same-sex couples would travel from other states to marry in Massachusetts.

That would translate into 330 jobs and a $111 million boost to the state’s economy, the study projects.