• The Supreme Court rejected a request by former top Donald Trump aide Steve Bannon to avoid jail time for defying a subpoena issued by the House committee investigating the Jan. 6 U.S. Capitol riot.
• Bannon must begin his four-month jail sentence Monday.
• Bannon was convicted of two counts of contempt of Congress in 2022.

The Supreme Court on Friday rejected a last-ditch effort by former Trump White House aide Steve Bannon to avoid reporting to jail next week while he appeals his conviction for defying a subpoena from a House committee investigating the Jan. 6, 2021, U.S. Capitol riot.

Bannon, 70, is due to begin serving a four-month jail sentence for contempt of Congress on Monday.

The Supreme Court in its unsigned, one-sentence order Friday said Bannon's "application for release pending appeal presented to The Chief Justice [John Roberts] and by him referred to the Court is denied."

The court in March rejected a similar request from Peter Navarro, another ex-advisor to former President Donald Trump, who also had been sentenced to four months in jail for defying a subpoena from the Jan. 6 House investigative panel. Navarro will soon complete serving his sentence.

An attorney for Bannon did not immediately respond to CNBC's request for comment on the Supreme Court's order.

Bannon was convicted in July 2022 of two counts of contempt of Congress after a trial in U.S. District Court in Washington, D.C. His jail sentence was stayed in October 2022 pending an appeal of his conviction.

Last month, a three-judge federal appeals court panel upheld his conviction, rejecting an argument that Bannon did not break the law because his attorney had advised him not to comply with the Jan. 6 committee's subpoena because of the chance his testimony could be blocked by a claim of executive privilege.

Bannon is expected to ask the full appeals court in Washington, D.C., to rehear the appeal of his conviction. But the district judge in his case, Carl Nichols, on June 6 ordered him to report to jail to begin his sentence.

Last week, Bannon asked the Supreme Court to suspend his surrender date pending his appeal. Friday's order by the high court rejected that bid, making it all but certain that Bannon will serve his sentence before his appeals are exhausted.

The bipartisan House panel was formed to investigate the Jan. 6 insurrection, when a violent mob of Trump's supporters stormed the U.S. Capitol and forced Congress to delay certifying President Joe Biden's 2020 election victory.

The committee set its sights on Bannon in light of reporting that on Jan. 5, 2021, he had predicted that "all hell is going to break loose" the following day, and that he was involved in talks about how to overturn the election results.