A federal judge in Washington on Monday sharply rebuked the attorney representing a Russian company fighting charges in a case brought by special counsel Robert Mueller III, raising uncertainty about whether the lawyer will continue to represent the company.

U.S. District Judge Dabney Friedrich of the District of Columbia upbraided Reed Smith partner Eric Dubelier, who represents Concord Management and Consulting, over what she described as “personal attacks” on the special counsel and federal prosecutors in recent filings. Pointing to his latest brief to the court, which included a reference to the 1978 movie “Animal House,” Friedrich described his comments as “unprofessional, inappropriate, and ineffective.”

Friedrich repeated that Dubelier's strategy—including using references to comedy movies— was “ineffective,” and sternly told him it was “undermining your credibility in this courthouse.”

“Knock it off,” Friedrich, an appointee of President Donald Trump, said.

Dubelier, in a tense exchange moments later, raised the prospect that he might no longer represent the company, given the judge's remarks. He told the judge he would need to speak to his client about those comments, which he described as personal attacks, and determine whether it made sense for him to continue representing the firm.

He angrily asserted that there had been “bias on the part of the court here.”

“There's no bias,” Friedrich responded, again telling Dubelier there had been “many inappropriate remarks” in his filings to the court. “You know it,” she said.

“That's your opinion,” Dubelier shot back, saying he was “entitled” to discuss it with his client. On that, the judge agreed.

The heated exchange came during a status hearing in the case, amid a fight in court papers between Concord Management and government prosecutors over discovery. Part of the dispute relates to whether Dubelier should be permitted to share some of the discovery that the government deems “sensitive” with Concord Management.

Concord Management is so far the only Russian defendant to answer to charges brought by the special counsel's office in the U.S. District Court for the District of Columbia. The firm has aggressively fought the special counsel and other federal prosecutors at every turn in the case, including by deploying colorful language and movie references in court papers.

In a Jan. 4 brief, seeking to compel discovery from the government, he likened an argument made by Mueller's office to a quote from the 1978 film, “Animal House.” Shortly after that filing, Friedrich announced a status conference hearing would take place.

After Monday's exchange between Friedrich and Dubelier, the judge sealed the courtroom to discuss another grand jury-related matter in the case.

At the hearing were prosecutors from the special counsel's office and the Justice Department's National Security Division and the U.S. Attorney's Office in Washington, D.C.

Dubelier, who was joined Monday by Reed Smith lawyer Katherine Seikaly, declined to comment after the proceeding.