MONTPELIER – The Senate Judiciary Committee unanimously approved a bill Friday extending marriage to same-sex couples in Vermont.

The 5-0 vote on the bill came after a week of testimony before the committee, as parents, religious leaders, civil rights experts and psychologists weighed in on the possibility of Vermont becoming the third state to allow same-sex couples to marry.

The full Vermont Senate is expected to vote on the bill Monday.

“I feel a step closer,” said Diane Shamas of Westminster West, who attended Friday’s Statehouse vote with her partner, Bari Shamas. “But I also know this isn’t over. It’s a long process.”

Beth Robinson, the attorney who successfully argued the court case that led to the civil union law, said that Friday’s committee vote was the next leg of a journey for gay and lesbian rights that started 15 years ago.

“This vote is certainly encouraging,” said Robinson, who works for the Vermont Freedom to Marry Taskforce. “But I don’t want to assume this is a done deal. We have a lot more education to do.”

Many observers expected the Senate Judiciary Committee to approve the bill, but the solid vote of support from all members came as a surprise. Several key lawmakers had declined to say how they would vote on the issue before Friday.

That included Sen. Kevin Mullin, R-Rutland, who sponsored an amendment Friday that would have instead placed the same-sex marriage question before the state’s voters as a non-binding referendum at the 2010 town meetings – one of the requests of several groups opposed to same-sex marriage.

“I believe our gay and lesbian brothers and sisters in Vermont would find much greater comfort to know that their friends, neighbors and families also agree that allowing same-sex couples to marry is a good idea,” Mullin said, in pushing for the amendment.

But Sen. Richard Sears, D-Bennington, the committee chairman, said he disagrees with using ballot referendums to gauge public reaction. Allowing for a town meeting vote next year would set up a major public relations battle – including the flux of out-of-state money – similar to the build-up to the Proposition 8 vote in California last year.

“It’s a slippery slope,” Sears said. “What’s the next step? Public referendums on gun laws?”

The amendment failed Friday morning with Mullin as the only committee member supporting it.

Steve Cable, a Rutland resident and spokesperson for the Vermont Marriage Advisory Council, a group opposed to same-sex marriage, said Friday’s vote was an outrage and predicted that voters will remember who voted yes when the next election rolls around.

“I think the voters in Rutland County will be extremely upset with Sen. Mullin,” Cable said.

Sen. John Campbell, D-Windsor, the vice-chairman of the Senate Judiciary Committee and a lead sponsor of the same-sex marriage bill, said he knows Mullin was concerned about the political fallout of supporting the bill, but said he took a “courageous stand.”

“Kevin is the real hero of the day,” Campbell said. “He took a stand and voted what he believes.”

Committee members also approved an amendment Friday morning that made some slight changes to the bill. The original bill contained language reaffirming the Constitutional right of churches to refuse to marry people if it disagrees with their faith.

But clergy and conservative religious leaders this week told lawmakers that they were worried that the provision was actually an attempt to, at some point in the future, force religious communities to perform same-sex marriages. Several religious leaders worried that their churches would be sued for not solemnizing same-sex marriages.

The altered language – which was approved in a 5-0 vote – made it clear that churches could not be sued in civil court. Campbell, a Catholic who added in the original provision, said it was an attempt at protecting religious freedoms.

“This is a civil marriage statute,” Campbell said. “It has nothing to do with religious marriage ceremonies.”

Contact Daniel Barlow at Daniel.Barlow@timesargus.com.