WASHINGTON (Reuters) - The legal team representing Richard Gates, a business associate of U.S. President Donald Trump’s former campaign manager, Paul Manafort, wants to stop representing him due to “irreconcilable differences,” according to a court filing unsealed on Wednesday.

Manafort and Gates were both indicted in October by Special Counsel Robert Mueller, as part of his ongoing investigation into whether the Trump campaign colluded with Russia.

Trump has denied any collusion occurred, and Russia has denied meddling in the U.S. election.

Shanlon Wu, Walter Mack and Annemarie McAvoy, the three lawyers representing Gates, first revealed their plans to withdraw from the high-profile criminal case last week, but the reasons for their request to drop the case were all under seal.

A closed-door hearing was held earlier on Wednesday on their motion to withdraw, but the judge has not yet issued a ruling on their request.

Manafort and Gates face charges including conspiracy to launder money, conspiracy to defraud the United States, and failure to register as foreign agents in connection with their political work for a pro-Russia Ukrainian party.

Both have pleaded not guilty.

Since last year, Manafort and Gates have both changed lawyers.

Manafort was previously represented by Reginald Brown at WilmerHale, but switched and hired Kevin Downing shortly after his Virginia home was raided by the Federal Bureau of Investigation in July.

Gates was initially represented by a federal public defender when he made his first court appearance in October before he tapped Wu.

He added McAvoy and Mack to his legal team later that fall.

CNN has previously reported that Gates has since hired Tom Green, an attorney at Sidley Austin.

However, Green has not filed a formal appearance in the public court docket, and was not present during Wednesday’s closed hearing.

Some have speculated that Gates could be changing his legal strategy or potentially considering a plea deal, though it remains to be seen.

Some of the reasons for why his lawyers are withdrawing from the case still remain under seal.

But in the one document made public on Wednesday, his lawyers wrote that due to the irreconcilable differences, it makes their “effective representation of the client impossible.”

A trial is expected sometime in the fall. Both Manafort and Gates are due to appear in court again on Feb. 14.