US President Joe Biden has rejected a bid by Donald Trump to withhold documents from a congressional investigation into the Capitol riot.
Mr Trump had asked that the records the committee requested remain hidden under executive privilege, which shields some presidential communications.
Meanwhile his former aide Steve Bannon vowed to resist a subpoena to appear before the inquiry.
The panel has threatened jail for any ex-officials who refuse to co-operate.
Mr Trump's supporters stormed the Capitol building in Washington on 6 January in a failed bid to overturn the certification of Mr Biden's election victory in November.
Hundreds of Mr Trump's supporters have since been arrested for their actions that day. Prosecutions continue.
In August the congressional investigating committee asked for records relating to the day's events, including communications from Mr Trump, members of his family, his top aides, his lawyers and other former members of his administration.
But Mr Trump argued he could claim executive privilege to prevent the documents from being handed over to the inquiry.
Legal scholars are divided on whether executive privilege can be asserted by former presidents. The issue is likely to set off a series of legal challenges to be determined by the courts.
On Friday the White House wrote to the National Archives saying that Mr Biden had "determined that an assertion of executive privilege is not in the best interests of the United States".
Mr Bannon's refusal to testify led members of the 6 January committee to threaten criminal contempt of Congress charges against him.
Democrats argue that Mr Bannon is employing a delaying tactic in an attempt to push back proceedings until after the midterm elections in November 2022, which may change the composition of the House of Representatives, the lower chamber of Congress.
"The whole game is to drag this out as long as possible, to see whether they can mobilise enough voter suppression to get Congress to change hands," Rep Jamie Raskin told US media, adding: "We're not going to let people play games and sweep evidence under the rug."
The committee has also ordered the testimony of Mr Trump's ex-Chief of Staff Mark Meadows; Dan Scavino, Mr Trump's social media manager; and Kash Patel, a former Pentagon chief of staff.
Mr Meadows and Mr Patel were co-operating with the inquiry, committee leaders Democrat Bennie Thompson and Republican Liz Cheney said in a statement.
US media report Mr Trump has asked all four former officials to refuse to comply with the inquiry.
On Friday Mr Trump - who has never conceded losing the election to Mr Biden - accused Democrats in Congress of using the committee to "persecute their political opponents".