Former U.S. Rep. Ed Case opened the headquarters of his campaign for a special congressional election in Hawaii yesterday with signwaving and an open house.

Case and two other announced candidates seek to fill the remainder of U.S. Rep. Neil Abercrombie's congressional term.

Abercrombie, a Democrat, has said he will resign on Feb. 28 to focus on his campaign for governor. The earliest an election can be held is May 1.

State Senate President Colleen Hanabusa also is running for Abercrombie's 1st Congressional District seat. She and Case are Democrats. The only Republican in the race is Honolulu City Councilman Charles Djou.

Case's office is on the corner of Kapiolani Boulevard and Piikoi Street. He represented Hawaii's 2nd Congressional District from 2003 through 2006.