Last month, Judge Carl Nichols of the DC District Court rejected Bannon's motion to dismiss the case against him, including his arguments that the House select committee's subpoenas were illegal and that he was protected by the secrecy of the presidency because he had been in contact with Trump at the end of his administration.

At trial, Justice Department prosecutors, who received a referral from the House to prosecute him, will need to prove a relatively narrow case if they are to secure a conviction -- that Bannon willfully refused to respond to the congressional inquiry. He will not be able to argue he relied on the advice of his lawyer, the judge has already ruled.