The Vermont Senate overwhelmingly approved on Monday a measure legalizing same-sex marriage.
After a 26-4 vote in the Senate, the House Judiciary Committee is expected to begin debating the gay marriage measure on Tuesday. The bill is also expected to be approved by the state House by next month.
If the bill becomes law, Vermont would become the third state after Massachusetts and Connecticut to allow same-sex marriage and the first state to permit gay and lesbian couples to marry by a vote of the Legislature.
Vermont was the first state in the country to enact civil unions for same-sex couples nine years ago.
Same-sex marriage bills are also gaining in other New England states.
The New Hampshire House of Representatives is scheduled to vote on a gay marriage bill later this week while a legislative panel in Maine will hold a hearing on a similar bill next month.
Rallying support against the pending legislation in the three states, the National Organization for Marriage launched a major ad campaign last week. Radio ads are airing in Vermont, New Hampshire and Maine, alerting listeners about the ramifications of legalizing same-sex marriage and how it could affect children.
According to recent surveys, the three New England states were listed as the least religious states in the country. The Gallup Poll Daily tracking and the 2008 American Religious Identification Survey placed Vermont on top with the most non-religious people.