Any prison sentence for Flynn would continue a precipitous fall for the former army lieutenant general, who after a long career in Iraq and Afghanistan was entrusted with shaping the Trump administration’s national security policy but became entangled early on in the FBI’s investigation into ties between the Trump campaign and Russia.

Flynn, who led «Lock Her Up» chants directed at Hillary Clinton during the Republican National Convention, is the only former White House official to have been charged in Mueller’s Russia investigation.

Retreat from responsibility

The sentencing recommendation bookends Flynn’s path from valued, high-level government co-operator to a defendant who prosecutors say no longer deserves any credit for helping the government.

«Indeed, the government has reason to believe, through representations by the defendant’s counsel, that the defendant has retreated from his acceptance of responsibility in this case regarding his lies to the FBI,» prosecutors wrote in seeking a sentence of up to six months.

«For that reason, the government asks this court to inquire of the defendant as to whether he maintains those apparent statements of innocence or whether he disavows them and fully accepts responsibility for his criminal conduct,» they added.

Sentencing is scheduled for Jan. 28.

Sidney Powell, a lawyer for Flynn, did not immediately respond to an email seeking comment. Defence lawyers will submit their own filing later this month.

Case has taken multiple twists

Flynn was to have been sentenced in December 2018 for lying to the FBI about his conversations with the then-Russian ambassador to the United States, including about his request that Russia not escalate tensions with the U.S. in response to sanctions imposed by the Obama administration for election interference.

But the hearing was abruptly postponed midway through at Flynn’s request after scathing criticism from U.S. District Judge Emmet Sullivan raised the prospect that he might send him to prison, even though prosecutors hadn’t recommended it. Flynn asked that the hearing be put off so that he could continue co-operating with prosecutors in hopes of avoiding any prison time.

The case has since taken a tumultuous turn.

The Justice Department opted not to have Flynn testify in the Virginia trial of a former business associate, saying that just before trial, he had changed his account and contradicted his own past statements. The decision denied Flynn a chance to be credited for that co-operation,

He also fired his lawyers and replaced them with new ones who have taken a strikingly contentious stance toward Mueller’s investigation, accusing FBI agents of effectively entrapping Flynn when they interviewed him at the White House and saying prosecutors had withheld documents and other information favourable to Flynn.

Conversations with Russian ambassador

Sullivan rejected each of the defence arguments in a lengthy opinion last month.

Flynn was seen as an important figure in the FBI’s investigation into whether the Trump campaign co-ordinated with Russia. He was interviewed at the White House days after Trump was inaugurated and pressed about his conversations during the presidential transition period with then-Russian Ambassador Sergey Kislyak.

Flynn is one of a half dozen Trump associates charged in the Mueller investigation, and at the time of his December 2017 guilty plea, he was the closest adviser to agree to co-operate with the probe. All six have either pleaded guilty or been found guilty in a jury trial.

Mueller found substantial contacts between Trump aides and Russia, but did not ultimately allege a criminal conspiracy to tip the 2016 election.