COLUMBUS, Ohio (AP) — The window has opened for county election boards to begin the official count in Ohio's deadlocked special congressional election.

Republican Secretary of State Jon Husted (HYOO'-sted) says Saturday is the first day that official canvassing can begin. The formal tally must be wrapped up by Aug. 24.

The Aug. 7 contest between Republican state Sen. Troy Balderson, of Zanesville, and Democrat Danny O'Connor, the Franklin County recorder, remains too close to call. Balderson leads O'Connor by less than a percentage point with thousands of ballots potentially left to be counted.

If the vote total remains within half a percentage point, an automatic recount will be triggered.

The two seek an open U.S. House seat made available by Republican Pat Tiberi's (TEE'-behr-eez) retirement in January.