PORTLAND, Maine — The state senator who sponsored Maine’s gay marriage law will serve a prominent role in Southern Maine Pride this weekend.

Sen. Dennis Damon, D-Hancock County, will serve as grand marshal of the parade, which begins Saturday at Portland’s Monument Square and ends with a festival in Deering Oaks.

Also on Saturday, Massachusetts Congressman Barney Frank will be a guest of the Maine Democratic Party at a fundraiser that’s billed as a celebration of the gay-marriage law. Frank said he will attend with his partner, Jim Ready, a Southern Maine resident.

Maine became the fifth state to allow gay marriage last month. Since then, New Hampshire has adopted a gay marriage law, as well.