An appeals court Thursday ordered the judge in Michael Flynn’s case to defend his actions after Flynn’s attorneys asked that his conviction be dismissed immediately, as requested by the Justice Department.

A three-judge panel of the U.S. Court of Appeals for the D.C. Circuit took the unusual step of ordering U.S. District Judge Emmet G. Sullivan to answer within 10 days accusations from Flynn, President Trump’s former national security adviser. The court also invited the Justice Department to comment.

The order comes as legal scholars from across the political spectrum debated the case’s implications for judicial independence and the Constitution’s separation-of-powers design.

“This case does not involve a decision by the Executive Branch simply to ‘drop’ a prosecution,” but a “virtually unprecedented decision” to dismiss a case after it has been won, wrote a group of about 20 legal experts, led by Harvard law professor Laurence H. Tribe, in a brief the group requested to file Friday.

Sullivan last week paused Flynn’s case and invited outside groups and a retired federal judge to argue against the Justice Department’s May 7 request to toss the former three-star general’s conviction. Sullivan also asked the retired judge to examine whether Flynn may have committed perjury while pleading guilty to lying about his pre-inauguration contacts with Russia’s ambassador.

Flynn’s attorneys responded Tuesday by asking the D.C. Circuit to intervene, accusing Sullivan of bias and overreaching into what they called prosecutors’ exclusive authority to decide whether to drop a case.

Sullivan’s orders “reveal his plan to continue the case indefinitely, rubbing salt in General Flynn’s open wound from the Government’s misconduct and threatening him with criminal contempt,” Flynn lawyer Sidney Powell wrote. Conservative legal analysts and commentators have also weighed in on the controversy, saying the Justice Department should be allowed to undo Flynn’s conviction without judicial interference.

“Under the American Constitution, the three separate branches are expected to clash with one another,” Tim Lynch, former director of the Cato Institute’s project on criminal justice, wrote recently for the Federalist Society. “Even still … judges must respect the prerogatives that fall within the constitutional boundaries of the executive branch. The prerogative to prosecute, or not prosecute, is one of those prerogatives.”

But others disagreed.

Tribe said his group will request to file a friend-of-the-court brief, saying the circuit panel’s order “makes it all the more urgent” and that the panel should deny Flynn’s request because granting it would be “a remarkable abuse of judicial authority.”

Requiring Sullivan to exonerate Flynn in the “public interest” as the government and Flynn request would make the court a “subordinate” of the Department of Justice and force it to be “complicit” in an “inexplicable about-face,” they wrote. They argued the federal judiciary would be treated as “an agency located on the executive branch organization chart headed by the President.”

Courts “do not simply do the bidding of the executive branch,” but instead have independent judicial authority, especially after a case has been fully prosecuted, a guilty plea entered and a sentence recommended, the brief argued. It said, “The separation of powers protects this Court’s authority to complete the resolution of this case, free from the interference of the Executive Branch.”

Tribe’s co-signers include constitutional law scholars, the former law school deans of Harvard, Yale and the University of Chicago, and the president of Columbia University. Republican signers include George T. Conway III, the conservative lawyer and husband of the president’s White House counselor, Kellyanne Conway; Trevor Potter, former Federal Election Commission chairman; and Richard Painter, George W. Bush’s former chief White House ethics lawyer.

Separately Friday morning, 16 former Watergate prosecutors urged the appeals court to reject Flynn’s petition, saying he had not exhausted his appeals and could come back if Sullivan refuses to dismiss his conviction.

The group argued judges are required “to exercise independent judgment when deciding a motion to dismiss federal charges.” They also argued that Sullivan’s preliminary “housekeeping orders” appointing a former judge to oppose the government’s motion and considering outside views “were entirely within that court’s powers.”

“Independent judgment is unquestionably informed by an adversary presentation in which not all parties are singing from the same hymnbook,” the former prosecutors wrote.

The prosecutors have asked to enter the case because the Trump Justice Department’s effort to exonerate Flynn “departs so dramatically from settled legal principles” and prosecutorial norms that it suggests it was “tailor made” because of his ties to the president, they said.

They cited Richard M. Nixon’s October 1973 order to fire the special prosecutor investigating the break-in at Democratic headquarters, which led his attorney general and deputy attorney general to resign in the “Saturday Night Massacre,” which triggered impeachment proceedings.

The appeals court order Thursday came from the D.C. Circuit came from Judges Karen LeCraft Henderson, Robert Wilkins and Neomi Rao.

In response to the order Thursday, Powell said, “Obviously the court is taking the issue very seriously, as it should.”

Federal judges generally cannot comment publicly on the merits of pending matters outside official proceedings. The Justice Department did not immediately respond to a request for comment.

Earlier this month, the Justice Department moved to toss out the guilty plea of the highest-ranking Trump adviser convicted in special counsel Robert S. Mueller III’s Russia investigation. The department concluded that Flynn should never have been interviewed by the FBI and therefore his lies concealing his Russian contacts were immaterial to any crime.

Critics dispute the department’s move, saying it distorted facts and appeared to serve the president’s personal political interests by giving an aide impunity to lie to government investigators.

Flynn pleaded guilty to lying in an FBI interview on Jan. 24, 2017, to conceal conversations with Sergey Kislyak, Russia’s ambassador at the time. The conversations involved talks before Trump took office about avoiding U.S. sanctions and other policies imposed late in President Barack Obama’s administration after Russia interfered in the 2016 presidential election.

Sullivan set oral arguments for July 16.