Florida’s tight Senate race was headed to a manual ballot recount Thursday after a machine tally of the state’s 8.2 million ballots showed a difference between Democrat Bill Nelson and Republican Rick Scott of less than 0.25 percent.

Scott picked up 865 votes in the machine recount, giving him a margin of 13,427 votes over Nelson, according to Scott's campaign. But that gain wasn't enough to avoid a state-mandated hand recount of all ballots.

The only way Florida might escape a hand recount is if Nelson agreed to concede the race, something he hadn't done as of late Thursday afternoon. Scott called on Nelson to concede after the machine recount that showed he gained more votes over Nelson.

“We need to put this election behind us, and it is time for Bill Nelson to respect the will of the voters and graciously bring this process to an end rather than proceed with yet another count of the votes, which will yield the same result, and bring more embarrassment to the state that we both love and have served,” Scott said in a statement Thursday following a 3 p.m. deadline for the state’s 67 counties to finish the machine recount.

But Nelson has signaled he has no plans to concede and has filed a string of lawsuits aimed at finding votes in his favor.

As a result, the manual recount will begin immediately in many counties. At the same time, local election officials are grappling with a court-ordered deadline extension for thousands of voters to correct irregularities on mail-in ballots that were previously rejected.

The manual recount deadline is Nov. 18, and voters have until Nov. 17 to correct ballots discarded for mismatched signatures under the state’s exact match law.

Nelson has held the seat since 2000 and is vying for a fourth term. Nelson believes the recount and extended deadline for voters to correct mail-in ballot problems will yield many votes in his favor and perhaps enough to push him ahead of Scott.