State Sen. Will Espero is expected to announce on Sunday whether he will enter the Democratic primary in urban Honolulu's 1st Congressional District.
U.S. Rep. Colleen Hanabusa is vacating the district to challenge U.S. Sen. Brian Schatz in the Democratic primary for Senate.
Honolulu City Councilman Stanley Chang is the only Democrat so far to commit to the CD1 race.
Espero is scheduled to be joined at the state Capitol by supporters and lawmakers such as state Rep. Rida Cabanilla, state Sen. Clarence Nishihara, Honolulu City Councilman Ron Menor, and former state Rep. Romeo Mindo.
Espero, who was appointed to the state House by Gov. Ben Cayetano in 1999, was elected to the House in 2000. He was elected to the Senate in 2002.