CNN  — 

Federal Judge Emmet Sullivan on Wednesday asked whether President Donald Trump’s former national security adviser Michael Flynn could be held in contempt of court for perjury.

Sullivan also appointed a retired judge to look into Flynn’s case and argue against the Department of Justice’s request to dismiss it.

Sullivan’s latest move is an enormous flex of judicial muscle six days after the Justice Department said it wanted to drop the Flynn case, unleashing a backlash across Washington of lawyers concerned with the politicization of the Justice Department.

Regarding Sullivan’s perjury question, Flynn has under oath told the judge he is both guilty and innocent of lying to the FBI about his contacts with Russia during the Trump transition.

Sullivan signaled on Tuesday he would open the door to third parties to weigh in on the case, but it wasn’t clear whom he would allow. Others have argued to him that the judge could sentence Flynn, essentially ignoring the Department of Justice’s motion to dismiss his charge.

Sullivan appointed a retired judge, John Gleeson, to act, in court parlance, as a “friend of the court” or amicus curiae, presenting arguments to the judge “in opposition to the government’s Motion to Dismiss” and on “whether the Court should issue an Order to Show Cause why Mr. Flynn should not be held in criminal contempt for perjury,” the judge wrote.

Gleeson is a former Clinton appointee to the federal trial bench in the Eastern District of New York. The Bronx-born lawyer served as a judge for 22 years and is now a partner in New York with the elite defense law firm Debevoise & Plimpton.

He co-authored an op-ed in the Washington Post on Monday, in which he outlined options Sullivan still had to learn more about the case, resolve questions regarding it and how he could, after some legal inquiry, sentence Flynn. The op-ed even made the suggestion Sullivan could appoint a third-party lawyer like Gleeson.

“There has been nothing regular about the department’s effort to dismiss the Flynn case. The record reeks of improper political influence,” the op-ed said.

It’s not unusual in appellate cases for third parties to represent additional legal viewpoints during arguments. But the situation is rare in criminal cases, where parties outside the prosecutors and defendants typically aren’t given a voice.

Sullivan, however, has opened up other closely watched proceedings to outside lawyers for additional information, including when he appointed a special prosecutor to review the bungled trial of the late Sen. Ted Stevens.

Gleeson’s firm also represents former acting Attorney General Sally Yates, who the Justice Department last week partially relied on to argue the case should be dismissed.

A spokesperson for the firm didn’t immediately respond to a request for comment.

This story has been updated with additional details on Gleeson and on Flynn’s case.