Attorneys for Michael Flynn, President Donald Trump's former national security adviser, released a memo Tuesday recommending 200 hours of community service and no time in prison.

Flynn's counsel said their client cooperated with the special counsel before his guilty plea and that his assistance in the investigation " began very shortly" after he was first contacted by prosecutors.

Flynn pleaded guilty in December 2017 to lying to the FBI regarding his communications with then Russian ambassador to the US Sergey Kislyak during the US presidential transition period, and he became a cooperating witness in the special counsel Robert Mueller's probe of Russian meddling in the 2016 election.

On December 4, Mueller's office released its own memo recommending a lenient sentence of as little as zero jail time for Flynn.

Attorneys for President Donald Trump's former national security adviser, Michael Flynn, released a memo Tuesday recommending a sentence of 200 hours of community service and no time in prison.

"General Flynn devoted his career to serving and protecting the Nation," Flynn's attorneys said in their memo. "Having made a serious error in judgment, for which he has shown true contrition, he recognized it was consistent with the values by which he has led his life simply to provide the facts to those charged with enforcing our laws."

"On the day he entered his guilty plea, he said he was 'working to set things right,'" the defense team added. "He has done so."

Flynn, a former 3-star general and onetime policy adviser to Trump's 2016 election campaign, pleaded guilty in December 2017 to lying to the FBI about his communications with then Russian ambassador to the US Sergey Kislyak during the presidential transition period.

Flynn became a cooperating witness in the special counsel Robert Mueller's probe of Russian meddling in the 2016 election.

On December 4, Mueller's office released a sentencing memo recommending a lenient punishment of as little as zero jail time for Flynn.

Donald Trump and Michael Flynn. John Locher/AP Photo

During the transition period between the Obama and Trump administrations in winter 2016, Flynn contacted Kislyak to request that Russia "vote against or delay" a UN resolution regarding Israeli settlements in Palestinian territory.

In separate conversations with Kislyak, Flynn asked the Russian government not to impose retaliatory sanctions on the US after the Obama administration sanctioned Russia for interfering in the 2016 election.

Additionally, Flynn was present in at least one meeting with Kislyak and Trump's son-in-law, Jared Kushner, during the transition period to discuss setting up a secret communications channel between the transition team and the Kremlin.

In the latest memo from the defense team, Flynn was said to have spent around 62 hours and 45 minutes in meetings with the special counsel, and produced thousands of documents to the Justice Department.

The special counsel's sentencing memo for Flynn recommended a sentence "at the low end of the range," including no jail time, for Flynn. The memo said Flynn met with the special counsel's office 19 times, and said he provided "substantial assistance" to the probe.

Read more: Mueller sent a clear message — and a warning — with Flynn's sentencing memo

The memo also said Flynn's cooperation early on the investigation provided enormous value in getting other witnesses to come forward, and he cooperated in multiple investigations. Large redacted portions of the Mueller memo referenced other inquiries in which Flynn testified or gave assistance.

His cooperation was "particularly valuable," the Mueller memo said, because Flynn was "one of the few people with long-term and firsthand insight" into the Trump campaign and transition team's contacts with Russia.

"If you read around all that black ink, Mueller did say enough to let us know this: Flynn gave up the goods, and Mueller's work is far from over," former federal prosecutor Elie Honig told INSIDER about Mueller's memo.

Flynn is set to be sentenced on December 18.

Read the full sentencing memo below »