More than 1,100 former federal prosecutors and Justice Department officials are calling on Attorney General William Barr to resign following reports Barr and President Donald Trump intervened in the criminal prosecution of Trumps friend Roger Stone .

In an open letter released Sunday , the former officials say Barr broke Justice Department rules when he overruled federal prosecutors in Stones criminal case, seeking a far more lenient sentence than the potential nine years prosecutors originally recommended.

It is unheard of for the Departments top leaders to overrule line prosecutors, who are following established policies, in order to give preferential treatment to a close associate of the President, they said.

In their call for Barrs resignation, the former Justice Department officials suggested his behavior is a threat to democracy.

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

Stone was convicted of lying to Congress and witness tampering in order to impede investigators looking into the Trump campaign. He was one of the highest-profile Trump allies to face prosecution resulting from special counsel Robert Muellers investigation into Russian interference in the 2016 election.

After prosecutors in the Stone case filed a sentencing request on Monday seeking up to nine years in prison, Trump called the decision a miscarriage of justice on Twitter.