State Senate President Colleen Hanabusa formally filed nomination papers yesterday for the May 22 special election to fill out the remainder of former U.S. Rep. Neil Abercrombie's term in Congress.

Former congressman Ed Case, the other Democrat in the race, filed his papers last Thursday. Honolulu City Councilman Charles Djou, a Republican in the race, plans to file next week.

The special election is a winner-take-all to serve out the final months of Abercrombie's term, which ends in January. Abercrombie resigned to campaign in the Democratic primary for governor.

Hanabusa, Case and Djou also plan to run in the September primary and November general election to replace Abercrombie in urban Honolulu's 1st Congressional District.