Steve Bannon, a long-time ally of former President Donald Trump, must report to prison by July 1 to serve his four-month sentence for defying a subpoena from the House committee that investigated the US Capitol insurrection, a federal judge ruled on Thursday.

US District Judge Carl Nichols in Washington granted the Justice Department’s request to make Mr Bannon begin his prison term after a three-judge panel of a federal appeals court last month upheld his contempt of Congress conviction.

Bannon is expected to seek a stay of the judge’s order, which could delay his surrender date. He told reporters outside court: “I’ve got great lawyers, and we’re going to go all the way to the Supreme Court if we have to.”

Mr Nichols, who was nominated to the bench by Mr Trump, a Republican, had initially allowed Bannon to remain free while he fought his conviction.

But prosecutors urged the judge to revoke his bond after a panel of the US Court of Appeals for the DC Circuit said all of Bannon’s challenges lack merit.

Prosecutor John Crabb told the judge it was “very unlikely” that the full appeals court or the Supreme Court would throw out Bannon’s conviction.

Bannon was convicted in 2022 of two counts of contempt of Congress: one for refusing to sit for a deposition with the January 6 House Committee and the other for refusing to provide documents related to his involvement in Mr Trump’s efforts to overturn his 2020 presidential election loss to Democrat Joe Biden.

Bannon’s lawyer at trial argued that the charges were politically motivated and that the former adviser did not ignore the subpoena but was still engaged in good-faith negotiations with the congressional committee when he was charged.

The defence has said Bannon had been acting on the advice of his attorney at the time, who told him that the subpoena was invalid because the committee would not allow a lawyer for Mr Trump to be in the room and that Bannon could not determine what documents or testimony he could provide because Mr Trump has asserted executive privilege.

Defence lawyer David Schoen told the judge it would be unfair to send Bannon to prison now because he would have already completed his sentence before he exhausts his appeals.

He said the case raises “serious constitutional issues” that need to be examined by the Supreme Court.

“In this country, we don’t send anyone to prison if they believe that they were doing something that complied with the law,” Mr Schoen told reporters.

A second Trump aide, trade adviser Peter Navarro, was also convicted of contempt of Congress. He reported to prison in March to serve his four-month sentence.

Navarro, too, had maintained that he couldn’t co-operate with the committee because Mr Trump had invoked executive privilege. But courts have rejected that argument, finding Navarro couldn’t prove Trump had actually invoked it.

The House January 6 committee’s final report asserted that Mr Trump criminally engaged in a “multi-part conspiracy” to overturn the lawful results of the 2020 election and failed to act to stop his supporters from attacking the Capitol, concluding an extraordinary 18-month investigation into the former president and the violent insurrection.