LEWISTON, Maine — Republican Sen. Garrett Mason plans to join the Maine governor’s race.

According to a campaign advisory, Mason is expected to make an announcement at 5 p.m. on Wednesday at Iron Horse Court in Lewiston. Mason would be the second Republican to enter the race.

There are currently 13 candidates in the race.

The 32-year-old Lisbon Republican is serving his second term as Senate majority leader and his fourth term in the Senate. He is barred from running for Senate again next year due to term limits.

Mason joins former Maine Department of Health and Human Services Commissioner Mary Mayhew in the Republican field. Mayhew announced her bid in June.