UPDATE: The bill has passed on a vote of 89 to 58. We'll have more on this as it develops.

AUGUSTA, Maine --The Maine House has begun floor debate of a same-sex marriage bill approved by the state Senate last week.

House Speaker Hannah Pingree says it's her goal to put the bill up for votes by day's end and send the bill back to the Senate for final approval.

The proposal would make Maine the fifth state to allow gay marriage, and supporters are confident of the bill's prospects because it has 50-plus sponsors. But it's unclear whether Gov. John Baldacci would sign the bill. Baldacci remains undecided.

Four states now allow same-sex marriages: Connecticut, Massachusetts and Iowa by court orders and Vermont through legislation. New Hampshire's Legislature is actively considering a gay marriage bill.