Federal prosecutors on Tuesday recommended that Michael Flynn, the first Trump national security adviser, receive a prison sentence for lying to FBI agents in the Russia investigation, abandoning their earlier support for leniency after the retired Army lieutenant general hired new lawyers who turned from cooperating to clashing with the government.

Coming just weeks ahead of his sentencing in Washington's federal trial court, the prosecutors' reversal provided the latest indication of how Flynn's relationship with the government soured in the two years since he pleaded guilty to lying about his contacts with the Russian ambassador to the United States. The government recommended zero to six months in prison for Flynn.

"The sentence should adequately deter the defendant from violating the law, and to promote respect for the law. It is clear that the defendant has not learned his lesson," prosecutors Brandon Van Grack and Jocelyn Ballantine said in the new filing Tuesday. "He has behaved as though the law does not apply to him, and as if there are no consequences for his actions."

The government asserted that Flynn, based on recent filings from his defense lawyers, is not entitled to cooperation credit for accepting responsibility.

Flynn's sentencing is scheduled for Jan. 28 before U.S. District Judge Emmet Sullivan of the District of Columbia.

Federal judges have wide discretion in punishing defendants and are not bound by the terms of any plea deal. Any prison sentence for Flynn would likely spur speculation about a pardon from President Donald Trump, who has publicly praised his former national security adviser and wished him "good luck."

Flynn, who in 2016 led the Republican National Convention crowd in a chant of "lock her up," resigned only weeks into Trump's tenure after it was revealed he misled Vice President Mike Pence about his contacts with the Russian ambassador to the U.S. during the transition.

Flynn pleaded guilty to lying to federal investigators about those communications and agreed to cooperate with the Russia probe. In the buildup to his initial sentencing date, in December 2018, prosecutors working under Special Counsel Robert Mueller III cited the extent of his cooperating in backing Flynn's bid for a sentence without prison time.

But his sentencing was delayed after a dramatic court hearing in which Sullivan appeared to question Flynn's patriotism and signaled he was weighing the possibility of sending Flynn to prison. Rather than go forward with the sentencing, Flynn, then represented by Covington & Burling, asked to be allowed to complete his cooperation with the government.

His cooperation would instead come to a halt. In June 2019, Flynn fired his defense team at Covington and hired Sidney Powell, an outspoken critic of the Mueller investigation.

Ahead of a trial in Alexandria, Virginia, federal court, where he was expected to appear as a star witness, prosecutors said they no longer planned to call Flynn to testify against a onetime business partner charged with secretly lobbying for Turkey. In court filings, prosecutors suggested they could no longer trust that Flynn would tell the truth in testifying against the former associate, Bijan Kian, who was charged in connection with their past lobbying work for Turkey.

In their filing Tuesday, prosecutors cited Flynn's "failure to complete his cooperation in—and his affirmative efforts to undermine—the prosecution of Bijan Rafiekian" in suggesting a sentence of up to six months in prison.

With Powell at his side, Flynn mounted a months-long attack on the Justice Department, accusing prosecutors of withholding favorable evidence and FBI agents of entrapping him in a 2017 interview concerning his past communications with Sergey Kislyak, at the time Russia's top diplomat in the U.S. Sullivan last month rebuffed those claims.

Emmet Sullivan U.S. District Judge Emmet Sullivan of the District of Columbia. Photo by Diego M. Radzinschi/ALM

"The court summarily disposes of Mr. Flynn's arguments that the FBI conducted an ambush interview for the purpose of trapping him into making false statements and that the government pressured him to enter a guilty plea," Sullivan wrote in his December ruling. "The record proves otherwise."

Prosecutors on Tuesday told Sullivan: "The defendant monetized his power and influence over our government, and lied to mask it. When the FBI and DOJ needed information that only the defendant could provide, because of that power and influence, he denied them that information."

Flynn's conduct, prosecutors asserted, "was more than just a series of lies; it was an abuse of trust."

Flynn's lawyers will get their chance later this month to tell Sullivan what they think should be an appropriate punishment.