Updated

A total of 15 Republican state attorneys general, led by Ohio Attorney General Dave Yost, filed an "amicus" brief in support of former national security adviser Michael Flynn on Monday, Fox News has learned.

The filing stated that the court needed to grant the DOJ’s motion to dismiss the case without commentary immediately “because such punditry disrobes the judiciary of its cloak of impartiality.” The short brief also elaborated on the problems that the court created by “inserting itself into the Justice Department’s exercise of prosecutorial discretion.”

On the recommendation of U.S. Attorney Jeff Jensen, who served as an FBI agent for more than a decade, the Justice Department earlier this month moved to drop its case against Flynn. The stunning development came after internal memos were released raising serious questions about the nature of the investigation that led to Flynn’s late 2017 guilty plea of lying to the FBI as his legal fees mounted.

One of the documents -- apparently concealed for more than two years in defiance of a court order -- was a top official's handwritten memo debating whether the FBI's "goal" was "to get him to lie, so we can prosecute him or get him fired." Other materials showed efforts by anti-Trump FBI agent Peter Strzok to pursue Flynn on increasingly flimsy legal grounds.

PIENTKA AND PRIESTAP MAY HOLD KEY TO UNDERSTANDING FLYNN BOMBSHELLS, GOP SAYS

After the DOJ pushed to dismiss the case, D.C. District Court Judge Emmet Sullivan issued an order last Tuesday indicating he would accept "amicus curiae," or "friend of the court" submissions -- drawing immediate scrutiny and a planned ethics complaint against Sullivan, who had previously refused to hear amicus briefs in the case.

“There was no reason to issue these orders because this Court has no say in the federal government’s decision not to prosecute,” the state attorneys general argued. “Simply put, the decision not to pursue a criminal conviction is vested in the executive branch alone — and neither the legislature nor the judiciary has any role in the executive’s making of that decision.”

FILE - In this May 1, 2008 file photo, U.S. District Judge Emmet G. Sullivan is pictured during a ceremony at the federal courthouse in Washington. The special prosecutor who investigated the botched case against late Alaska Sen. Ted Stevens is not recommending criminal charges against any of the Justice Department attorneys who tried him despite finding widespread misconduct beyond what has yet been publicly revealed.  (AP Photo/Charles Dharapak)

Judge Emmet Sullivan has a reputation for punishing Department of Justice overreach, including during the case against then-Alaska Republican Sen. Ted Stevens. (AP)

In addition to Yost, the brief was signed by attorneys general from Alabama, Alaska, Arkansas, Florida, Georgia, Indiana, Louisiana, Mississippi, Missouri, Oklahoma, South Carolina, Texas, Utah, and West Virginia.

The submission came days after nearly 2,000 ex-DOJ employees condemned the DOJ's motion to dismiss the Flynn case, in what journalist Matt Taibbi called a "melodramatic group email somberly reported as momentous news."

The GOP amici are going up against a sealed amicus brief that 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 included Jill Wine-Banks -- who previously advanced unsubstantiated collusion theories involving the Trump campaign and Russia -- as one of its members. ("Mueller can prove conspiracy with Russia beyond any doubt," Wine-Banks previously wrote. She also claimed in 2017 that Flynn would receive "immunity for kidnapping as well as his federal crimes.")

President Trump last week retweeted a post by the Twitter user Techno_Fog calling Wine-Banks a "Trump/Russia collusion nutter." The post concluded, sarcastically: "Good job Judge Sullivan!"

It would not be unprecedented for the government to successfully move to dismiss a case after securing a conviction. In fact, Sullivan himself tossed the conviction of former Alaska Sen. Ted Stevens in 2009, when it emerged the government had not produced a slew of exculpatory "Brady" material.

On Monday, retired federal judge John Gleeson, who was appointed by Sulivan to submit a brief arguing against the Justice Department's motion to dismiss the Flynn case, asked for oral arguments to take place following the submission of written briefs.

Gleeson suggested a deadline of June 10 for his initial brief – to be followed by the Justice Department's response as well as Gleeson's reply to that response – and then oral arguments from both sides.

Gleeson has openly criticized the Trump administration's handling of Michael Flynn's case, raising concerns that he was selected to improperly bolster Sullivan's efforts to keep the Flynn case alive even though both the government and defendant want it dismissed.

Sullivan previously suggested Flynn may have committed treason, in a bizarre 2018 courtroom outburst, and seemingly confused key details about Flynn's overseas lobbying work.

Then, last December, Sullivan accused Flynn's legal team of plagiarism in a filing, saying they had "lifted verbatim portions from a source without attribution." Flynn attorney Sidney Powell shot back that the claim "made no sense," and that she relied on one of her own cases as well as a brief primarily written by a friend whom she cited.

CLICK HERE TO GET THE FOX NEWS APP

More recently, Sullivan has suggested he isn't bothered by the FBI's missing FD-302 witness report of agents' January 24, 2017 White House interview with Flynn. “[T]hings happen and documents are lost," Sullivan stated. "I mean, it just happens.”

Former FBI SWAT agent James Gagliano called that a "shockingly cavalier" reaction by Sullivan.

Gagliano, who initially defended the FBI's Flynn probe, has more recently said Flynn was "railroaded," after this month's bombshell revelations.

Fox News' David Spunt and The Associated Press contributed to this report.