(CNN) Republican former US Attorney General Alberto Gonzales on Monday slammed the FBI director's recent actions in the investigation into Hillary Clinton's email server.

He called Comey's actions an "error in judgment" and said he is "somewhat perplexed about what the director was trying to accomplish here."

Gonzales said Comey's letter Friday informing lawmakers that the FBI is reviewing new emails potentially related to its investigation into Clinton's use of a private email server as secretary of state breaks from long-standing Justice Department practice. The protocol is not to comment on investigations and to stay silent on politically sensitive matters less than 60 days from an election.

"You don't comment on investigations because commenting on the investigation may jeopardize the investigation. And that's the box that he's put himself in, because people are now calling for more information -- for release of the emails," Gonzales told CNN's John Berman and Kate Bolduan on "At This Hour."

He was the third former attorney general to recently and publicly criticize Comey.

Gonzales, who served in the George W. Bush administration, said Comey wouldn't have been misleading voters by withholding the news until after November 8.

"If you delay the announcement, hopefully it's not going to jeopardize an investigation, it's not going to jeopardize the pursuit of justice, and voters will have the opportunity to vote on Election Day without information that may in fact be incomplete or untrue," he said.

Comey was the deputy attorney general under Gonzales -- making him the second-highest ranking figure in the Justice Department during the latter half of Bush's presidency.

Gonzales cast Comey as someone who won't budge once he's made a decision.

"He is a person that, you know, he does what he thinks is right and then he doesn't deviate from that position despite the pressure. And he may be wrong," Gonzales said.

"My experience is, is that once he takes a position, he digs in, and he's just not going to move from it, whether he's wrong or not, and whatever political pressure may be put to bear on him. He's just not going to move from it. And you know, there is virtue in that, but there is also some danger in that."

Eric Holder

Former Attorney General Eric Holder also criticized Comey's decision Monday. Writing in The Washington Post on Monday , Holder called Comey's decision "incorrect."

Obama's first attorney general said Comey's letter to Congress announcing a review of the new emails was "a stunning breach" of law enforcement protocol and one that carried "potentially severe implications" during a presidential campaign.

"I served with Jim Comey, and I know him well. This is a very difficult piece for me to write. He is a man of integrity and honor. I respect him. But good men make mistakes. In this instance, he has committed a serious error with potentially severe implications," Holder wrote.

"It is incumbent upon him -- or the leadership of the department -- to dispel the uncertainty he has created before Election Day. It is up to the director to correct his mistake -- not for the sake of a political candidate or campaign but in order to protect our system of justice and best serve the American people."

Attorney General Eric Holder (L) and FBI Director James Comey (R) leave after a major law enforcement action announcement at the Justice Department June 30, 2014 in Washington.

The former Attorney General wrote that Comey's letter "violated long-standing Justice Department policies and tradition" not to comment publicly about politically sensitive investigations within 60 days of an election.

"It ran counter to guidance that I put in place four years ago laying out the proper way to conduct investigations during an election season. That guidance, which reinforced established policy, is still in effect and applies to the entire Justice Department -- including the FBI," he wrote.

Holder argued Comey "broke with these fundamental principles" with the announcement of the review.

"I fear he has unintentionally and negatively affected public trust in both the Justice Department and the FBI," Holder wrote. "And he has allowed -- again, without improper motive -- misinformation to be spread by partisans with less than pure intentions."

Holder acknowledged the charged political environment surrounding the Clinton email investigation, writing that he was "mindful" of the perception created by former President Bill Clinton's tarmac meeting with current Attorney General Loretta Lynch over the summer during the FBI's probe of the case.

But he added that "the solution was not for the FBI director to announce the department's decision about whether to proceed" with additional investigation or review of the newly discovered emails.

Michael Mukasey

Former US attorney general Michael Mukasey slammed Comey Monday for the way he handled the situation, saying he should not "have been in this fix."

"This wasn't Comey's call. It is not his function as director of the FBI to decide who gets charges and doesn't. It's his function to gather evidence. And he didn't fulfill that function very well," Mukasey told CNN's Erin Burnett on "Erin Burnett OutFront." "But it's certainly not his function to get up and pronounce on whether charges should be brought or whether a reasonable prosecutor would ever bring them."

He added: "I don't think he should have been this fix. I don't think he should have put either himself or the bureau or the Justice Department in this fix."

But Mukasey, who served under George W. Bush after Gonzalez, said that Democrats calling Comey's actions a violation of the Hatch Act, which bars political activity by federal employees, "baloney."

"That's baloney," he said. "I mean, you know, it's sort of an amusing talking point for three and a half seconds, but it's not serious."

He also slammed Comey's decision in a Wall Street Journal op-ed , calling omey's original decision in July not to indict the Democratic presidential candidate "unworthy." He described the decision as one to "accede to the apparent wish of Obama that no charges be brought against Clinton."

As such, he claimed this earlier move makes Comey's letter to Congress irrelevant.

"Regardless of what is in the newly discovered emails, the current Justice Department will not permit a grand jury to hear evidence in this case. And because only a grand jury can constitutionally bring charges, that means no charges will be brought," Mukasey wrote. "Which is to say, we know enough to conclude that what we don't know is of little immediate relevance to our current dismal situation."