(CNN) -- The Vermont House on Thursday passed a same-sex marriage bill by 95-52, which is not enough of a margin to override a veto promised by the governor.
Republican Gov. Jim Douglas has said he does not support the sam-sex marriage bill.
The vote came late in the day after five hours of debate before a crowded chamber, said the group Vermont Freedom To Marry, in a posting on its Web site.
"It's a testament to the power of telling our stories," said Beth Robinson, a spokeswoman for the group. "We know we've got more work to do in the run-up to the override vote."
Last week, the bill passed the Senate 26-4.
A final House vote is slated for Friday, when the bill is to be sent back to the Senate for approval of changes in the legislation sought by the House, and then to the desk of Gov. James Douglas, whose threatened veto could be overridden by a two-thirds vote.
That override vote could take place as soon as Tuesday, Robinson said.
Douglas, a Republican, has left little doubt about where he stands. "I believe our civil-union law serves Vermont well and I would support congressional action to extend those benefits at the federal level to states that recognize same-sex unions," he said last week in a written statement.
"But, like President Obama and other leaders on both sides of the aisle, I believe that marriage should remain between a man and woman."
Vermont Senate President Pro Tem Peter Shumlin, the main sponsor of the bill, has described Douglas' decision as "cowardly."
"You cannot veto love and commitment between two people," the Democrat said. "This is a civil-rights issue. It is time for the governor to show some courage."
Massachusetts and Connecticut are the only states that have passed same-sex marriage laws.