U.S. Rep. Charles Djou has formally become a candidate for re-election.

Djou filed his candidacy papers today at the state Office of Elections’ headquarters in Pearl City.

A former member of the City Council, Djou is the first Republican in two decades to represent Hawaii in the U.S. House.

In May, Djou bested two Democrats and 11 lesser-known candidates for the right to fill the remaining few months in the post formerly held by Democratic Rep. Neil Abercrombie.

He faces no major opposition for the Republican nomination for a full two-year term.

But he could have a tough battle in November against his likely Democratic foe, state Senate President Colleen Hanabusa.