State Sen. Clayton Hee has scheduled an announcement for Sunday at `Iolani Palace on a bid for office.
Sources say the chairman of the Senate Judiciary and Labor Committee will challenge Lt. Gov. Shan Tsutsui in the Democratic primary.
Hee is in his second stint in the state Senate. He also served as trustee for the state Office of Hawaiian Affairs and in the state House.
Hee made unsuccessful bids for lieutenant governor in 2002 and for Congress in 2006.
Tsutsui, the former state Senate president, became lieutenant governor in 2012 after Gov. Neil Abercrombie appointed then-Lt. Gov. Brian Schatz to the U.S. Senate to replace the late U.S. Sen. Daniel Inouye.