Mr Herbert also accused Barr of “a dangerous abuse of power” in protecting Donald Trump in the letter, which ABC News says it has confirmed as authentic.
A serving US attorney says Bill Barr ‘brought shame’ on the Department of Justice in a searing letter.
Federal prosecutor James Herbert said he was forced into action by Mr Barr’s speech earlier this month in which he accused his own lawyers of “headhunting.”
Mr Herbert, who is an assistant US attorney for the district of Massachusetts, wrote that Mr Barr had overseen an “unprecedented politicisation of the office of attorney general.”
“From his misleading summary of the Mueller Report, to his selective intervention in cases against political allies of the president, to his accusation that victims such as George Floyd are being used as mere “props” by those calling for racial justice, to his baseless claims about mail-in ballots, William Barr has done the president’s bidding at every turn,” he wrote.
“For 30 years I have been proud to say I Work for the Department of Justice, but the current attorney general has brought shame on the department he purports to lead,” he concluded.
A spokesman for his office told ABC News that Mr Herbert “remains employed in their office.”
In the speech at Hillsdale College on 17 September, Mr Barr called his prosecutors a “permanent bureaucracy” that abuse their power by “headhunting” high-profile targets.
“Under the law, all prosecutorial power is vested in the attorney general,” he insisted.
“And these people are agents of the attorney general. As I say to FBI agents, “Whose agent do you think you are?”
“Now, I don’t say this in a pompous way, but that is the chain of authority and legitimacy in the Department of Justice.”