HARRISBURG (AP) — Voters in heavily Republican northcentral Pennsylvania have a special election date set to elect a new representative to the U.S. House after the five-term incumbent resigned just three weeks into the new congressional term.

Gov. Tom Wolf said Thursday he scheduled the special election to coincide with Pennsylvania's primary election on May 21.

Republican Tom Marino's last day in office was Wednesday. Marino, R-12, was a strong ally of President Donald Trump's and easily won a fifth term in November, but the 66-year-old abruptly announced his resignation last week, saying only that he's taking a job outside government.

The sprawling 12th congressional district covers all or parts of 15 counties, and Republicans are heavily favored, with about 100,000 more registered voters than Democrats.

Political party committee members or delegates will pick nominees.