ATLANTA — As the candidates in the disputed race for Georgia governor retreated further into their corners, counties across the state on Thursday began a court-ordered process of reviewing absentee ballots and counting those previously rejected for missing or incorrect dates of birth.

Georgia Secretary of State Robyn Crittenden issued guidance to counties to review the absentee ballots, count those rejected for missing or incorrect dates of birth and recertify results if the counts change. She set a deadline of 5 p.m. Friday.

The campaign of Democrat Stacey Abrams has ratcheted up its attacks on Republican Brian Kemp, while Kemp continues to claim that results certified by county election officials confirm he has an “insurmountable lead.”

At a news conference Wednesday, Georgia Democrats cast doubt on the legitimacy of any election count that ends with former secretary of state Kemp being certified as the winner of a fiercely fought election against Abrams, who’s seeking to become the first black woman elected governor in the U.S.

“We believe that Brian Kemp mismanaged this election to sway it in his favor,” said Abrams’ campaign manager Lauren Groh-Wargo, surrounded by Democratic lawmakers at the Georgia Capitol.

Democrats beyond Georgia have started to echo the notion that a Kemp victory would be illegitimate. Ohio Sen. Sherrod Brown said Wednesday that if Abrams loses, it’s because Republicans stole the election.

Kemp’s campaign, which has repeatedly called on Abrams to concede, repeated that call Wednesday, saying Abrams and her supporters have used “fake vote totals,” “desperate press conferences” and “dangerous lawsuits” to try to steal the election.