More than 2,000 former DOJ officials call on Attorney General William Barr to resign Last week Barr told ABC News, Trump's tweets make doing his job "impossible."

More than 2,000 former Department of Justice officials are calling on Attorney General William Barr to resign, according to the group Protect Democracy.

"Political interference in the conduct of a criminal prosecution is anathema to the Department's core mission and to its sacred obligation to ensure equal justice under the law," according to the group, which has been critical of the administration in the past.

The nonpartisan, nonprofit group said that the attorney general has "flouted" that fundamental principal.

The former DOJ officials said it is "outrageous" the way Barr interfered in the Roger Stone case.

"Although there are times when political leadership appropriately weighs in on individual prosecutions, it is unheard of for the Department's top leaders to overrule line prosecutors, who are following established policies, in order to give preferential treatment to a close associate of the President, as Attorney General Barr did in the Stone case," they wrote.

The group claims that Barr has done the president's bidding and that those actions have caused damage to the Department of Justice. The letter was signed by officials appointed from both Democrat and Republican administrations, according to Protect Democracy.

The officials commended the actions of the four line prosecutors who resigned from the Stone case and called on more to resign.

"We call on every DOJ employee to follow their heroic example and be prepared to report future abuses to the Inspector General, the Office of Professional Responsibility, and Congress; to refuse to carry out directives that are inconsistent with their oaths of office; to withdraw from cases that involve such directives or other misconduct; and, if necessary, to resign and report publicly -- in a manner consistent with professional ethics -- to the American people the reasons for their resignation."

The number of former DOJ officials who signed the statement nearly doubled since Monday morning.

On Monday, Donald Ayer, a former deputy attorney general under George H.W. Bush and former U.S. Attorney, said Barr needed to resign in an op/ed in the Atlantic. Barr was attorney general under Bush, but Ayer did not serve with him.

"All of this conduct -- including Barr's personal interventions to influence or negate independent investigations or the pursuit of criminal cases, and his use of the department's resources to frustrate the checks and balances provided by other branches -- is incompatible with the rule of law as we know it, and especially as it has functioned since Levi's Watergate reforms," Ayer wrote, referring to Edward Levi, who was the attorney general appointed after President Richard Nixon resigned. He was tasked with restoring credibility to the department.

The Department of Justice has not returned ABC News' request for comment.

The calls for resignation come as Barr spoke out for the first time to ABC News Chief Justice Correspondent Pierre Thomas.

The attorney general said that President Donald Trump has never asked him to interfere in a criminal case. Barr said that Trump's tweets, however, "make it impossible for me to do my job."

"I think it's time to stop the tweeting about Department of Justice criminal cases," Barr told ABC News.

"I'm not going to be bullied or influenced by anybody ... whether it's Congress, a newspaper editorial board, or the president," Barr said. "I'm gonna do what I think is right. And you know … I cannot do my job here at the department with a constant background commentary that undercuts me."

A senior adviser to the president told ABC News that while Trump is not happy with Barr's interview with Thomas, his confidence in the attorney general remains steadfast.

ABC News' Kyra Phillips and Alexander Mallin contributed to this report.