The House of Representatives is expected to vote on Thursday to refer Steve Bannon to federal prosecutors for potential criminal charges relating to his defiance of Congress over the investigation into the 6 January Capitol insurrection.

Donald Trump’s former chief strategist in the White House is facing deepening legal peril as he continues to refuse to cooperate with the House select committee investigating the Capitol violence. On Tuesday, the nine-member committee, including two Republicans, voted unanimously to recommend criminal prosecution after Bannon refused to comply with a subpoena calling for him to provide documents and to testify.

Should the full House decide to recommend contempt charges, the case is likely to pass to federal prosecutors in Washington, who would then have the power to convene a grand jury. Any final decision to charge Bannon would likely be taken at the highest levels of the justice department, given the extreme sensitivity of the case and the exceptionally rare nature of contempt of Congress prosecutions.

Should he be convicted of contempt, Bannon faces up to a year in prison and a fine of up to $100,000.

The House committee investigating the 6 January insurrection has been steadily tightening the screws on Bannon. At Tuesday’s hearing, Liz Cheney, the representative from Wyoming who has been a leading critic of Trump’s role in inciting the 6 January assault in which five people died, directly accused Bannon of planning the attack.

“Based on the committee’s investigation, it appears that Mr Bannon had substantial advanced knowledge of the plans for January 6 and likely had an important role in formulating those plans,” she said. Cheney added that Bannon and Trump’s refusal to comply suggested that “President Trump was personally involved in the planning and execution of January 6th”.

The committee has released a 26-page report setting out its case for why Bannon, the former executive chairman of the rightwing Breitbart News, should be held accountable to Congress. In it, Bannon is said to have played “multiple roles”, including “his role in constructing and participating in the ‘stop the steal’ public relations effort that motivated the attack [and] his efforts to plan political and other activity in advance of January 6th”.

The investigators make special reference to a gathering of the Trump campaign’s legal team on the eve of 6 January at the Willard Hotel, two blocks from the White House. Trump’s personal lawyer Rudy Giuliani was present with Bannon and together they reportedly contacted several Republican Congress members encouraging them to block the certification of Biden’s victory.

Also present was Roger Stone, the political dirty trickster, who left the hotel with bodyguards drawn from the far-right militia group the Oath Keepers.

According to Peril, the book by Bob Woodward and Robert Costa, Bannon spoke to Trump from the Willard Hotel. They discussed the then vice-president Mike Pence’s resistance to playing along with the attempt to subvert the election result.

The committee report also quoted at length from Bannon’s War Room podcast which he posted on 5 January. He said: “It’s not going to happen like you think it’s going to happen,” he told his listeners. “OK, it’s going to be quite extraordinarily different. All I can say is, strap in. Tomorrow it’s game day. So strap in. Let’s get ready.”

Bannon added: “So many people said, ‘Man, if I was in a revolution, I would be in Washington.’ Well, this is your time in history.”

Trump has instructed Bannon and other former aides who have been served subpoenas by the House committee not to cooperate. Earlier this month the former president’s lawyers sent a letter to the individuals saying that they were covered by executive privilege.

President Biden has formally rejected that argument, saying that the issue of executive privilege is decided by him and that in his opinion it would not be “in the best interests of the United States” to grant it in this case.

On Tuesday, Trump lashed back by suing the House committee investigating 6 January. The legal complaint said that the demand for documents was “nothing less than a vexatious, illegal fishing expedition”.