WASHINGTON — Rick Gates, the former deputy campaign manager for Donald Trump and ex-business partner of Paul Manafort, faces sentencing Tuesday in a federal courtroom here.

His lawyers tell U.S. District Judge Amy Berman Jackson that his extensive cooperation with federal prosecutors should result in a sentence of probation instead of jail time, and the government does not oppose that idea.

Gates and Manafort were the first former Trump campaign officials to be charged by former special counsel Robert Mueller's prosecutors, accused of evading taxes and violating federal lobbying laws by concealing millions of dollars they earned representing pro-Russian politicians in Ukraine. Manafort was convicted after a jury trial in Alexandria, Virginia, and pleaded guilty to related charges in a separate case in Washington. He is serving a seven-and-a-half-year sentence in federal prison.

Instead of fighting the charges as Manafort did, Gates pleaded guilty. He agreed to cooperate with Mueller's team and, after the special counsel's office was disbanded, with the U.S. attorneys' offices in Washington and Alexandria. His lawyers and federal prosecutors say he has done everything asked of him.

Court documents show he met with investigators at least 50 times, spending more than 500 hours with government lawyers and federal agents. He testified as a prosecution witness during Manafort's trial and in the trials of longtime Trump friend Roger Stone and Washington lawyer Greg Craig, who did legal work for Manafort.

Gates provided "extraordinary assistance," federal prosecutors said in their memo telling the judge they would not oppose his request for probation. "Gates has worked earnestly to provide the government with everything it has asked of him."

A longtime business consultant, Gates joined Manafort's lobbying firm in 2006 and worked closely with him for years. Their friendship made the Gates testimony against his former boss at Manafort's trial all the more dramatic.

Gates signed on to the Trump campaign in March 2016 as deputy campaign manager and later served as deputy chairman of the Trump inaugural. He and Manafort were indicted in October 2017. Gates pleaded guilty the following February.

His lawyer, Thomas Green, also urged Jackson not to impose a fine, explaining that Gates has been unemployed since his indictment and has depleted his savings and investment accounts. His lawyers are representing him at no charge, Green said.

Gates has tried to turn his life around and has been "meeting with a psychologist to help him with issues relating to emotional well being and life choices," his lawyers said in their pre-sentencing submission to the judge.

By Tuesday, all defendants charged by the Mueller team will have been sentenced except Michael Flynn, who was briefly Trump's national security adviser. His sentencing is set for Jan. 28.