The laws take effect Sept. 1 in Vermont and in mid-September in Maine, though conservative groups there are trying to collect 55,000 signatures in three months to challenge the law at the polls.

Lynch made his announcement amid a flurry of gains for same-sex marriage in the region. Last month, Vermont lawmakers overrode a governor's veto to legalize gay marriage; last week, Governor John E. Baldacci of Maine signed a similar bill after it passed his state's Legislature.

John Sununu, former governor and current head of the state's Republican Party, said Lynch had "wiggled out of his commitment to traditional marriage."

Amid the accolades for Lynch, there was sharp criticism for his change of heart on the issue. Kevin H. Smith, who led the in-state campaign against the bill as executive director of Cornerstone Policy Research, said Lynch had "broken his trust with New Hampshire voters."

Representative James Splaine, the primary sponsor of the same-sex marriage legislation, said: "We can find a way to do that in the next week or two, and then we'll have marriage equality."

"I applaud the governor for keeping an open mind," Senate president Sylvia Larsen said in an interview last night. "The language that we will be addressing only improves the protections for religious organizations and individuals."

While Lynch warned he would veto the bill if lawmakers do not add his language to the legislation, activists and politicians on both sides of the issue said they viewed Lynch's proposed language as a subtle, technical adjustment, making legalization of same-sex marriage in New Hampshire all but a done deal. The Senate president and House speaker announced quickly that they thought the changes would be made.

"Throughout our history, our society's views of civil rights have constantly evolved and expanded," Lynch said in a nearly 600-word statement. He cited New Hampshire's tradition of landing "on the side of individual liberties and protections," adding, "That is what I believe we must do today."

Lynch, a Democrat, had loomed as a possible obstacle in New Hampshire. The governor had supported civil unions but consistently opposed gay marriage. But his thinking changed, he said yesterday.

Lynch's announcement sets New Hampshire, once viewed as a conservative enclave in a liberal region, on course to become the sixth state in the country - and the fourth in the last six weeks - to allow same-sex couples to marry. It would leave Rhode Island as the sole New England state to prohibit gay marriage.

Governor John Lynch, appearing to pave the way for same-sex marriages in New Hampshire, announced yesterday that he would sign a bill legalizing the unions as long as the state Legislature made it clearer that religious groups would not be forced to conduct "marriage ceremonies that violate their fundamental religious beliefs."

The bill progressing in New Hampshire would allow same-sex couples to marry starting Jan. 1, 2010.

"We are further than we ever thought we would be at this point," said Janson Wu, a staff attorney for Gay & Lesbian Advocates & Defenders, the Boston-based advocacy group that has pushed for three decades to end discrimination against gays and lesbians. "It's really exciting."

The group's lawyers waged the court cases that led to gay marriage in Connecticut and Massachusetts, and its staff has worked to build support across the region. Last fall, the organization announced a campaign to legalize same-sex marriage throughout New England by 2012.

What had seemed to be an optimistic goal is now almost complete. The organization will now turn its attention toward Rhode Island.

When Massachusetts became the first state in the nation to issue marriage licenses to same-sex couples in 2004, New Hampshire seemed unlikely to follow, even with its "Live Free or Die" motto and history of individual liberty. Republicans had enjoyed virtually uninterrupted control of both houses of the Legislature since the late 19th century.

But in 2006, the same Granite State voters who unseated a pair of GOP congressmen amid rising unpopularity for the Iraq war and the presidency of George W. Bush, also swept Democratic majorities into the State House. A few months later, the new Legislature approved civil unions.

Two weeks ago, when the New Hampshire House approved gay marriage by a 186-to-179 vote, Lynch reiterated his position that civil unions were best for the state. The bill appeared to falter in the Senate, but lawmakers crafted an amendment to protect religious freedom. That version won the support of 13 of 14 Democrats but none of the Republican senators, for a 13-11 tally.

Lynch built on the Senate amendment in proposing his wording, which stresses that religious groups would not need to marry gay couples or otherwise acknowledge their unions.

Smith, who opposed the bill, said that wording was merely cover for politicians to reverse their position.

"The folks who [they are] claiming to be protecting in this bill are already protected in the First Amendment by the freedom of religion," he said. "The folks who are not protected are your individual business owners, caterers, photographers, who now will be forced to provide these services for same-sex weddings."

Beyond New England, Iowa is the only state in which gay couples are allowed to marry, the result of a court ruling there last month. California previously issued marriage licenses to same-sex couples but ceased doing so after voters passed Proposition 8 last year.

Opponents of gay marriages say that their hopes for preserving marriage as the domain of heterosexual couples only lie with voters.

"Every time the citizens are allowed to vote, even in California, citizens vote for marriage to mean the union between one man and one woman," said Kris Mineau, president of the Massachusetts Family Institute. A majority of the public recognizes "that the primary role of marriage is children," he said. "It takes a father and mother to create a child, and every child has an inalienable right to be raised by a father and mother."

Splaine said New Hampshire's politicians have reflected the public will. Politicians, he said, have been driven by personal stories and a critical mass of openness, acceptance, and demystification.

"Harvey Milk's advice in 1978 - 'Come out, come out, wherever you are' - was an important message," said Splaine, who came out as a gay lawmaker in 1980. "When people see that we're their friends, their co-workers, their family members, it becomes much more difficult for people to discriminate."

© Copyright 2009 Globe Newspaper Company.