Democratic Senate leaders have said that if the panel became deadlocked, they would yank the measure from its committee and force a vote before the full Senate. That is allowed under a rarely used provision of the Hawaii Constitution if more than one-third of senators approve.

At least 18 of the 25 senators have said they favor civil unions. The measure already has passed the Hawaii House, but with one vote less than would be needed to override a veto.

Republican Gov. Linda Lingle has not stated her position on the bill, which would make Hawaii the fifth state to allow same-sex civil unions. Under the state constitution, the earliest the bill can be pulled to the Senate floor is March 10.