Steve Bannon and other former top officials in the Trump administration are facing legal peril for defying subpoenas issued by the House select committee investigating the Capitol attack, as the panel prepares to pursue criminal referrals for non-compliance.

The legal jeopardy for Bannon – who is expected to be held in contempt by the committee on Tuesday – is anticipated after it emerged in a letter to his attorney, obtained by the Guardian on Monday, that he had claimed executive privilege protections on materials unrelated to the executive branch.

The...