President Trump's former campaign manager Paul Manafort departs U.S. District Court after a motions hearing in Alexandria, Virginia, May 4, 2018.

Former Trump campaign boss Paul Manafort "repeatedly and brazenly" broke the law, special counsel Robert Mueller said in a court filing unsealed Saturday.

"The crimes he engaged in while on bail were not minor; they went to the heart of the criminal justice system," Mueller wrote in a sentencing memorandum in U.S. District Court in Washington, D.C.

In the massive 800-page document, Mueller said that federal sentencing guidelines suggest Manafort get between 17 and nearly 22 years of incarceration when he is sentenced in the D.C. court on March 13.

But Mueller did not recommend that Judge Amy Berman Jackson impose a particular prison sentence on the longtime Republican operative. Jackson can sentence Manafort to a maximum of 10 years in prison due to statutory requirements.

However, the special counsel did call for a stiff sentence, highlighting Manafort's "bold" criminal actions and extensive pattern of deceit that "remarkably went unabated even after indictment."

Manafort, 69, is also due to be sentenced in a separate case brought by special counsel prosecutors in federal court in Alexandria, Virginia, on March 8. Mueller has already said in that case that under sentencing guidelines Manafort could face up to 24 years behind bars, and pay up to tens of millions of dollars in fines.

If the judge in the D.C. case sentences Manafort to prison time, she can decide whether to add it to his sentence in the Virginia case or allow it to be served at the same time.

Both cases involve crimes connected to the millions of dollars Manafort earned from consulting work he performed in Ukraine for a pro-Russia political party before joining the Trump campaign. The partially redacted sentencing memo appears to provide no details about Manafort's interactions with Russians during the 2016 presidential campaign – an area Mueller's team has been investigating as part of the ongoing probe of Russian meddling in that election.

Manafort was convicted in August on eight counts, including tax and bank fraud, in the Virginia case. On the eve of his D.C. trial in September, Manafort struck a deal with the special counsel and pleaded guilty to two counts of conspiracy, in which he acknowledged tampering with potential witnesses in his case.

But the deal fell apart months later, after Manafort was accused of lying to investigators in breach of the agreement.

Those alleged lies should weigh heavily on Manafort's sentencing, Mueller said in the memo to the D.C. judge. His conduct after pleading guilty "reflects a hardened adherence to committing crimes and lack of remorse," the special counsel said.

Manafort's "deceit, which is a fundamental component of the crimes of conviction and relevant conduct, extended to tax preparers, bookkeepers, banks, the Treasury Department, the Department of Justice National Security Division, the FBI, the Special Counsel's Office, the grand jury, his own legal counsel, Members of Congress, and members of the executive branch of the United States government," Mueller said.

"In sum, upon release from jail, Manafort presents a grave risk of recidivism," the special counsel stated.

Meanwhile, authorities in New York are reportedly preparing to slap criminal charges on Manafort in anticipation of a possible pardon from Trump, who has railed against the special counsel for his treatment of his former campaign boss.

In August, Trump lamented in a tweet: "Looking back on history, who was treated worse, Alfonse Capone, legendary mob boss, killer and "Public Enemy Number One," or Paul Manafort, political operative & Reagan/Dole darling, now serving solitary confinement - although convicted of nothing? Where is the Russian Collusion?"

Lawyers for Manafort are scheduled to file their own sentencing memo in the D.C. case on Feb. 25. They then face a March 1 deadline to submit sentencing documents in the Virginia case, at which point Mueller will have up to five days to respond.