The last undecided House race in the country could be resolved as early as Sunday, according to central Ohio election officials.

State Sen. Steve Stivers (R) leads Franklin County Commissioner Mary Jo Kilroy (D) by about 400 votes out of about 259,555 ballots counted so far in Ohio’s 15th Congressional district.

But that number is likely to change starting Saturday, when officials will begin counting 26,000 provisional ballots from Franklin County. The Ohio Supreme Court ruled Friday afternoon that Franklin County could not count an additional 1,000 provisional ballots without voter names and signatures on the envelopes — a ruling that allowed election officials to proceed with counting the remaining 26,000 provisional ballots in what was one of the closest House races in the country.

Franklin County Board of Elections spokesman Ben Piscitelli said officials hope to finish counting the provisional ballots on Saturday and certify the election on Sunday.

But this weekend could be just the beginning of a two-week process for Kilroy and Stivers. State law mandates an automatic recount if the difference between the two candidates is less than one-half of one percent — a process that would begin Dec. 12 at the earliest if Franklin County officials certify the election results on Sunday as planned.

Piscitelli estimated that a recount could take about five days, which means a winner would be named in mid-December.

It’s unclear just how the 26,000 remaining provisional ballots will affect the race, although most Ohio operatives think it will boost Kilroy’s chances of taking the seat of retiring Rep. Deborah Pryce (R). Franklin County is the more Democratic part of the district; plus, provisional ballots traditionally break for Democrats.

But because Franklin County straddles two Congressional districts, many of the ballots could include votes for the 12th district race. What’s more, because the ballots are sealed, it’s unclear how many of the ballots included votes in any Congressional race.