Nearly 2,000 US Department of Justice (DOJ) and FBI officials signed an open letter on Monday calling for the resignation of Attorney General William Barr, saying the decision to abandon the prosecution of Michael Flynn was “extraordinarily rare, if not unprecedented.”

Those who signed include officials who served both in the Republican and Democratic administrations, most notably Start Gerson, who served as acting attorney general during Clinton’s presidency. The open letter strongly criticized the decision of the Attorney General to abandon prosecution of Flynn and encouraged Congress to formally censure Barr from failing to act in the public interest.

Flynn, accused of lying under oath to FBI officials about open conversations during transitions with the Russian ambassador, pleaded guilty back in 2017, but the DOJ dropped all charges earlier this month.

The letter states, “Governments that use the enormous power of law enforcement to punish their enemies and reward their allies are not constitutional republics; they are autocracies.”