The filings add prominent voices to the backlash against Attorney General William Barr's softening of criminal prosecutions against President Donald Trump's associates.
In legal memos sent to the court on Monday and obtained by CNN, the former prosecutors essentially laid out the legal footing they believe Judge Emmet Sullivan has to reject the dismissal request and sentence Flynn, who had pleaded guilty to lying to the FBI.
They compared the current situation at the Justice Department to Watergate, the scandal and criminal investigation that led to the President Richard Nixon's resignation.
The group, calling themselves friends of the court or "amici" in legal parlance, "experienced the 'Saturday Night Massacre,' during which an honorable Attorney General and an honorable Deputy Attorney General resigned or were dismissed rather than obey the instructions of a self-interested President to frustrate the work of an independent Special Prosecutor," they wrote to the judge.
"The parallels and the contrasts between the Watergate affair and the present situation now before this Court make manifest that Amici have a direct and substantial interest in the proper disposition of the pending Motion directed by the incumbent Attorney General to protect a close ally of the President."
In addition, the former prosecutors say they offer a "unique perspective on the need for independent scrutiny and oversight to ensure that crucial decisions about prosecutions of high-ranking government officials are made in the public interest, are viewed as legitimate and are not subsequently reversed by political intervention."
The filing appears to have at least contributed to an announcement from Sullivan that essentially keeps the case alive. Tuesday, the judge announced he would consider legal arguments from third parties, including people with "unique information or perspective," before deciding what to do on Flynn's case.
The Watergate alumni's full legal argument isn't yet available, and it's not yet known how many groups or individuals will try to become part of the Flynn proceedings.
The former prosecutors are: Nick Akerman, Richard Ben-Veniste, Richard J. Davis, Carl B. Feldbaum, George T. Frampton, Jr., Kenneth S. Geller, Gerald Goldman, Stephen E. Haberfeld, Henry L. Hecht, Paul R. Hoeber, Philip Allen Lacovara, Paul R. Michel, Robert L. Palmer, Frank Tuerkheimer, Jill Wine-Banks and Roger Witten.
It's been less than a week since the Justice Department said it wanted to drop Flynn's prosecution. The department argued Flynn should not have been investigated, and thus not interviewed in the White House in January 2017, where he lied to the FBI about his communications with Russia.
The drumbeat from former federal prosecutors has grown since last Thursday.
Almost 2,000 former Justice Department employees have signed an open letter urging Sullivan "to closely examine the Department's stated rationale for dismissing the charges." They suggested the judge could hold hearings with witnesses testifying and move forward to sentence Flynn.
"If ever there were a case where the public interest counseled the court to take a long, hard look at the government's explanation and the evidence, it is this one," the former employees, organized by Protect Democracy, a non-profit accountability group, wrote in a statement published on the website Medium.
The group will attempt to file a brief in the Flynn case, according to Ben Berwick, a counsel with Protect Democracy, told CNN.
Flynn's legal team pushed back almost immediately on Sullivan's announcement, writing that the judge should not allow third parties to chime in and urging the judge to dismiss Flynn's case immediately. The filing from Flynn's defense lawyers acknowledged that the former Watergate prosecutors had sought to be heard in the case.
"There are countless people -- including former prosecutors on both sides of the parties -- who would like to express their views, but there are many reasons there is no provision for outsiders to join a criminal case in this Court," Flynn's defense lawyers wrote on Tuesday. "Of course, the former prosecutors are all free to submit opinion pieces to assorted media outlets -- as many have already done -- but this Court is not a forum for their alleged special interest."
They also argued that Sullivan has no choice but to dismiss the case.
"This travesty of justice has already consumed three or more years of an innocent man's life -- and that of his entire family. No further delay should be tolerated or any further expense caused to him and his defense," they added.