Former U.S. President and University Distinguished Professor Jimmy Carter urged in a letter to Brian Kemp, Georgia’s Republican gubernatorial candidate, to resign from his post as Georgia secretary of state, according to the Associated Press.  

Kemp has been accused of delaying at least 53,000 predominantly black voter applications, because his office uses an “exact match” policy to verify the applications, according to AP. A federal judge on Thursday issued an injunction to prevent Georgia from rejecting absentee ballots because of mismatched signatures after several civil rights groups sued.

The 39th president, who served as Georgia governor from 1971 to 1975, wrote on Oct. 22 that Kemp should relinquish his position to ensure a fair race, as the secretary of state oversees the election.

“In Georgia’s upcoming gubernatorial election, popular confidence is threatened not only by the undeniable racial discrimination of the past and the serious questions that the federal courts have raised about the security of Georgia’s voting machines, but also because you are now overseeing the election in which you are a candidate,” Carter wrote. “I urge you to step aside and hand over to a neutral authority the responsibility of overseeing the governor’s election.”

Kemp Campaign Communications Director Ryan Mahoney responded to Carter’s letter by suggesting that Carter and Democratic gubernatorial candidate coordinated the attack, according to the National Public Radio (NPR).

“It’s sad that she’s using the former president to do her dirty work,” Mahoney said.

Kemp has refused to step down as Georgia secretary of state despite repeated calls to do so.

“While outside agitators disparage this office and falsely attack us, we have kept our head down and remained focused on ensuring secure, accessible, and fair elections for all voters,” Kemp said in a statement to CNN. “The fact is that it has never been easier to register to vote and get engaged in the electoral process in Georgia, and we are incredibly proud to report this new record.”

Democratic gubernatorial candidate Stacey Abrams tweeted about Kemp’s controversy and assured her voters that his alleged effort will not impede her campaign.

“Feels like deja vu: 4 years ago, Kemp tried to keep 40k new voters off the rolls. It took a few years, but we beat him,” Abrams wrote. “A few months ago, he tried to close polling places, but we beat him there too. Now he’s at it again, and we’ll beat him — again.”