PORTLAND — Hundreds of gay marriage supporters are expected at a rally to launch the final campaign push for legalizing same-sex marriage.

Mainers United for Marriage is expecting up to 500 people at Thursday evening’s get-out-the vote rally in Monument Square. Organizers say the rally will feature speakers and serve as a “call to action” in the final days of the campaign.

After the rally, gay marriage supporters are being encouraged to walk to Portland City Hall and cast in-person absentee ballots.

Residents on Tuesday will vote on a ballot question seeking to legalize same-sex marriage in Maine.