Rick Gates, a former aide to President Trump, will plead guilty to fraud-related charges in the coming days and will testify against Paul Manafort, his former business partner who once ran the Trump campaign, according to a report Sunday.

“Rick Gates is going to change his plea to guilty,” the Los Angeles Times reported, citing a person knowledgeable of the development.

He will revise his plea in federal court in Washington, DC, in the “next few days.”

Gates and Manafort were indicted last October by special counsel Robert Mueller on charges they laundered millions of dollars they were paid while working for a pro-Russian leader in Ukraine.

They both pleaded not guilty.

The charges are part of Mueller’s investigation into Russian interference in the 2016 election and any collusion on the part of Trump campaign associates.

The Times report said that cooperation by Gates, who has been in talks with Mueller’s team over the past several weeks, could result in a “substantial reduction in his sentence” — possibly just 18 months.

One of the final issues being discussed is Gates forfeiting any cash or other valuables he may have received in his illegal activities.

A lawyer involved in the investigation said Gates, who is married and has four children, doesn’t seem able to put up an expensive, high-powered defense.

“He can’t afford to pay it,” the lawyer told the Times. “If you go to trial on this, that’s $1 million to $1.5 million. Maybe more, if you need experts” to appear as witnesses.

Manafort joined the Trump campaign in March 2016 and was fired in August 2016 when reports surfaced that he received improper payments from his one-time client, former Ukrainian Prime Minister Viktor Yanukovych.