WASHINGTON (AP) — Former President Donald Trump’s longtime ally Steve Bannon on Thursday appealed his criminal conviction for defying a subpoena from the House committee investigating the Jan. 6 insurrection at the U.S. Capitol.

Bannon’s attorney argued he didn’t ignore the subpoena, but was trying to avoid running afoul of executive privilege objections Trump had raised.

“Mr. Bannon acted in the only way he understood from his lawyer that he was permitted to behave,” attorney David Schoen said, adding that Bannon was wrongly blocked from making that argument at trial.

Prosecutors, though, said Bannon was no longer working at the White House during the runup to Jan. 6 and refused to work with the committee to determine if there were questions he could answer. “Stephen Bannon deliberately chose not so comply in any way with lawful congressional subpoena,” said prosecutor Elizabeth Danello.

The U.S. Court of Appeals for the District of Columbia Circuit took the case under consideration.

Bannon, 69, was convicted last July of two counts of contempt of Congress and later sentenced that August to four months in prison. U.S. District Judge Carl Nichols put the sentence was on hold as his appeal played out, later saying in court documents he expected the case to be overturned.

A second Trump aide, trade advisor Peter Navarro, was also convicted of contempt of Congress this past September and has also vowed to appeal. The House panel had sought their testimony about Trump’s efforts to overturn the 2020 presidential election.

The House Jan. 6 committee finished its work in January, after a final report that said Trump criminally engaged in a “multi-part conspiracy” to overturn the lawful results of the 2020 election and failed to act to stop a mob of his supporters from attacking the Capitol.

Bannon is also set to go on trial next May on separate money laundering, fraud and conspiracy charges in New York related to the “We Build the Wall” campaign. He has pleaded not guilty.

He has pleaded not guilty to charges alleging he falsely promised people that all donations would go toward building a wall along the U.S.-Mexico border. Instead, prosecutors allege that the money was used to enrich Bannon and others involved in the project.