(NewsNation) — A judge agreed Monday to extend the deadline to return absentee ballots for voters in a suburban Atlanta county who didn’t receive their ballots because election officials failed to mail them.

Janine Eveler, the director of elections in Cobb County, said it was a mistake by her office. The ballots were marked in the system as though they had been sent out, but they never made it into the mail.

“We are so sorry to these voters. I mean, we’re sick about it,” Eveler said. “It was a case of everybody thinking you have the flash drive with all the data, and the person just didn’t follow through.”

The American Civil Liberties Union and the Southern Poverty Law Center sued over the mistake Sunday and asked a judge to extend the deadline for returning the ballots. The group argued in the suit that “hundreds of Cobb County voters are on the brink of disenfranchisement.”

Eveler wrote in an email to the county election board that because of staff error, ballots were never created nor sent on two days last month, the lawsuit states.

“We know it wasn’t the voters’ fault, we know it wasn’t the post office’s fault,” said Daniel White, an attorney for the elections office, according to The Atlanta Journal-Constitution. “This was an administrative error.”

During the three weeks of early voting that precede Election Day, election officials are supposed to send out ballots within three days of receiving a request. Voters then have until 7 p.m. on Election Day to return their ballots.

The newspaper reports that Cobb County Superior Court Judge Kellie Hill planned to sign a consent order Monday afternoon to allow the county to accept ballots that are postmarked by Election Day, even if they’re received later.

The Atlanta suburb of Cobb County is home to roughly 766,000 people, and Georgia is one of the most closely watched states this midterm election. The Senate race between Democratic Sen. Raphael Warnock and Republican candidate Herschel Walker is neck and neck.

Elections staff in Cobb County are overnighting absentee ballots to hundreds of voters, including Ka Long. He requested his absentee ballot weeks ago and was told it was sent, but it didn’t show up until Monday.

“I got it probably 20, 30 minutes ago, filled it out, rushed over here and had to submit it,” Long said.

The Associated Press contributed to this report.