On Thursday, a former White House strategist who was a top lieutenant of President Trump, Stephen Bannon, will be in court to find out whether he will have to serve time in prison after being convicted of contempt of Congress more than a year ago.

In October 2022, Bannon was convicted on two counts of contempt for refusing to comply with a subpoena issued by the House select committee to investigate the January 6 attack on the Capitol.

Bannon’s case arises out of the District Court for the District of Columbia and is being appealed at the Washington, D.C., Circuit Court of Appeals, where a three-judge panel will hear his case starting Thursday.

In the case, Bannon’s attorneys argue that he was a “lay person” at the time he received the subpoena and that he did not knowingly violate the law. “He did not ‘willfully’ violate the law,” Bannon’s attorneys wrote in a filing, “he retained experienced counsel and followed counsel’s advice and directives at all times.”

Bannon’s lawyer, David Schoen, also claims that Bannon was protected by executive privilege as invoked by Mr. Trump on October 5, 2021, and that Bannon was told by his former attorney that he did not need to comply with the subpoena.

If Bannon’s appeal fails to get his conviction overturned, he will likely be forced to serve the sentence that was handed down last October — four months in prison.

A conviction for contempt of Congress is punishable by a fine of up to $100,000 and anywhere between one and 12 months in prison.

After Bannon’s conviction last year, the attorney for the District of Columbia, Matthew Graves, said that the “subpoena to Stephen Bannon was not an invitation that could be rejected or ignored.”

“Mr. Bannon had an obligation to appear before the House select committee to give testimony and provide documents,” Mr. Graves said. “His refusal to do so was deliberate, and now a jury has found that he must pay the consequences.”

The proceedings Thursday are not the only events on Bannon’s calendar in the near future. He is due in court in late May 2024 at Manhattan on multiple charges of money laundering and conspiracy.

Prosecutors in New York brought a state-level case against Bannon for his alleged efforts to defraud donors in his “We Build The Wall” fundraising scheme after Mr. Trump pardoned Bannon of federal charges related to the scheme in his final days in office.