Nine Democratic senators called on Attorney General Bill Barr to resign on Friday over his intervention in ex-Trump adviser Roger Stone’s criminal case to water down federal prosecutors’ recommended prison sentence after President Donald Trump complained about it.

Sens. Bernie Sanders (I-VT), Elizabeth Warren (D-MA), Richard Blumenthal (D-CT), Edward Markey (D-MA), Patty Murray (D-WA), Jeff Merkley (D-OR), Chris Van Hollen (D-MD), Ron Wyden (D-OR) and Mazie Hirono (D-HI) sent Barr a scathing letter ripping the Justice Department’s “unethical political intervention” in the case.

“The interference in this case by you or other senior DOJ officials working under you is a clear violation of your duty to defend fair, impartial, and equal justice for all Americans,” they wrote. “As a result, we call on you to resign immediately.”

The Democrats accused Barr of meddling “in a clearly political fashion” to shield Stone on Trump’s behalf after the political adviser was found guilty of obstructing Congress and witness tampering in Special Counsel Robert Mueller’s Russia probe.

“The shocking actions taken by you or your senior staff to seek special protections for Mr. Stone make a mockery of your responsibilities to seek equal justice under the law and reveal that you are unfit to head the DOJ,” the senators wrote. “A DOJ that abandons the rule of law in order to give sweetheart deals to criminals acting on behalf of the President of the United States is as corrupt as it is unacceptable.”

Shortly after the Democratic lawmakers sent the letter, news broke that Barr currently has prosecutors questioning the federal lawyers involved in former Trump campaign adviser Michael Flynn’s criminal case, another case Trump has repeatedly disparaged.

Read the letter below: