The judge in Donald Trump’s civil business fraud trial barred attorneys in the case Friday from commenting on “confidential communications” between him and his staff, after the former president’s attorneys renewed claims that a clerk is poisoning the proceedings.

Threatening “serious sanctions” for any violations, Judge Arthur Engoron expanded on a prior gag order that prohibited parties in the trial from speaking publicly about court staffers. The earlier order didn’t mention the parties’ attorneys, but Engoron had suggested Thursday he might expand it.

The matter seized attention on a day when Eric Trump, one of the former president’s sons and a top executive in the family business, wrapped up his testimony. He said he relied completely on accountants and lawyers to assure the accuracy of financial documents that are key to New York Attorney General Letitia James’ lawsuit.

The state lawsuit accuses Trump and his company of deceiving banks and insurers by exaggerating his wealth on his annual financial statements. Trump and other defendants, including sons Eric and Donald Trump Jr., deny the allegations.

The former president and current Republican 2024 front-runner is due to testify Monday in the case, which threatens the real estate empire that launched him into the public eye and, eventually, politics.

Like the earlier gag order, the new one was sparked by criticism of the judge’s principal law clerk, Allison Greenfield. She has unexpectedly become a lightning rod during the trial.

“The First Amendment right of defendants and their attorneys to comment on my staff is far and away outweighed by the need to protect them from threats and physical harm,” wrote Engoron. He said his office has gotten “hundreds of harassing and threatening phone calls, voice mails, emails, letters and packages” during the trial.

In response, a spokesperson for Trump lawyer Alina Habba called the case “an attempt to silence the left’s top political opponent.”

“There should be no doubt at this point that politics is now permeating our courts,” the spokesperson, Erica Knight, wrote in a statement. She warned of “a dangerous precedent which diminishes the integrity of the judicial system.”

Hours earlier, Trump attorney Christopher Kise had recapped complaints that the defense team has raised for over a week about the clerk’s notes to the judge during testimony.

The contents of the notes have not been disclosed. But Trump’s lawyers say the messages are more frequent when the defense is questioning witnesses, and the attorneys suggest the notes are tilting the process against their case.