Flynn’s lawyers lodged their objections to the government’s conduct in a joint status report filed on Friday with the Washington, D.C., federal court.
Lawyers for the government countered that Flynn is ready for sentencing, perhaps as soon as Oct 21.
Both sides agreed that Flynn’s cooperation with various government probes is finished.
Flynn pleaded guilty in December 2017 to lying to the FBI about his conversations the prior December with Sergey Kislyak, who was Russia’s ambassador to the United States, about US sanctions imposed on Moscow by President Barack Obama.
That plea came in connection with Special Counsel Robert Mueller’s since-completed probe into Russian interference in the 2016 US election.
Flynn’s sentencing was originally scheduled for December 2018, and US District Judge Emmet Sullivan will need to decide whether a further delay is warranted.
In Friday’s status report, Flynn’s lawyer Sidney Powell said she has not had enough time to review the case, and accused the government of unfairly refusing to hand over information relevant to the defence.
She said this includes transcripts and recordings of phone calls supposedly underlying the charges against Flynn, and which the government has “steadfastly refused to produce.”
Lawyers for the US Department of Justice countered that the government has “exceeded” its disclosure obligations, and was unaware of any classified information that Flynn needed to review.
The Justice Department proposed that Flynn be sentenced between Oct 21 and 23 or between Nov 1 and 15.
Flynn’s lawyers asked for 90 days before issuing of another status report.
Flynn’s discussions with Kislyak occurred in the run-up to Trump’s January 2017 inauguration, after Flynn had worked on Trump’s election campaign.
In connection with his plea, Flynn had been expected to testify at a trial last month against former business partner Bijan Rafiekian, who had been accused of secretly lobbying for Turkey.
But prosecutors called off Flynn’s testimony on July 9, saying they instead planned to portray the retired US Army lieutenant general as Rafiekian’s co-conspirator.
Rafiekian was convicted two weeks later.
Flynn lasted three weeks as Trump’s first national security adviser.