D.C. District Court Judge Emmet Sullivan issued an order Tuesday indicating he'll soon accept "amicus curiae," or "friend of the court" submissions, in the case of former national security adviser Michael Flynn -- drawing immediate scrutiny and a planned ethics complaint against Sullivan, who had previously refused to hear amicus briefs in the case.

Sullivan's order indicated that an upcoming scheduling order would clarify the parameters of who specifically could submit the amicus briefs, which are submissions by non-parties that claim an interest in the case. Sullivan specifically said he anticipated that "individuals and organizations" will file briefs "for the benefit of the court," as he prepares to rule on the government's motion to dismiss the case.

"Judge Sullivan, who denied leave to file amicus briefs when he knew third parties would have spoken favorably of Flynn, now solicits briefs critical of Flynn," independent journalist Michael Cernovich wrote on Twitter Tuesday evening. "This is a violation of the judicial oath and applicable ethical rules. We will be filing a complaint against Sullivan. ... [He] is acting as a politician, not a judge."

Sullivan had previously held in the Flynn case that "[o]ptions exist for a private citizen to express his views about matters of public interest, but the Court's docket is not an available option."

Will Chamberlain, a lawyer and the editor-in-chief of Human Events, noted that case law in the circuit generally prohibits trial court judges from second-guessing the government's decision not to prosecute a defendant.

Fox News is told that movement on Cernovich's ethics complaint was underway Tuesday night, and that Cernovich also was considering filing his own amicus brief. (Cernovich has also sought to intervene in the case of Trump associate Roger Stone to obtain jury questionnaires, after issues of apparent juror bias surfaced -- an ongoing effort supported by the Reporters Committee for Freedom of the Press.)

Flynn's legal team indicated in a filing Tuesday that a sealed amicus brief has already been submitted by a left-wing group known as the "Watergate Prosecutors," urging Sullivan not to toss out Flynn's guilty plea despite the Justice Department's request. That group was featured in an October 2019 Washington Post opinion piece, and listed Jill Wine-Banks -- who previously advanced unsubstantiated collusion theories involving the Trump campaign and Russia -- as one of its members.