A referendum to legalize same-sex marriage in Washington is a strong favorite to pass next month, according to a new poll released over the weekend.

The poll, conducted by SurveyUSA and commissioned by KING-5 News in Seattle, shows 55 percent of likely voters support Referendum 74, which would affirm a law signed by Gov. Christine Gregoire (D) in February that made Washington the seventh state to legalize marriage for same-sex couples.  Only 40 percent are opposed to the measure.

Polls have consistently shown around 50 percent support for Referendum 74, as evidenced by the PollTracker Average.