On a 4-3 vote, a Washington state Senate committee on Thursday passed and sent to the full Senate a bill to legalize same-sex marriage in the state.

The Senate Government Operations, Tribal Relations and Elections Committee approved the measure, after defeating a proposed amendment by Sen. Don Benton, R-Vancouver, that would have required sending the gay marriage law to the voters for approval.

It’s not known when the full Senate will vote on the bill.

The same-sex marriage bill was introduced carrying the names of 23 state Senate sponsors, and two other senators have publicly stated they will vote for the bill, giving supporters the 25 votes needed for passage in the Senate. The bill has more than enough votes in the state House.

Gov. Christine Gregoire has pledged to sign a gay marriage bill into law.

Same-sex marriage is currently legal in six states – New York, Connecticut, Iowa, Massachusetts, New Hampshire, Vermont -- and the District of Columbia.