The Democratic-led US House of Representatives on Wednesday voted to approve "contempt of Congress" charges against Peter Navarro and Daniel Scavino, two former aides to ex-President Donald Trump, over their failure to co-operate with the inquiry into the January 6, 2021 Capitol riot.
Legislators voted 220 to 203, which would refer the matter to the Department of Justice for a decision on whether to press criminal charges. Liz Cheney and Adam Kinzinger were the only Republicans to vote in favour.
Mr Navarro, a former trade adviser to Mr Trump, and Mr Scavino, who was a deputy chief of staff, did not comply with subpoenas to appear before the House select committee investigating the attack.
Mr Scavino and Mr Navarro have said that their communications are protected by executive privilege.
But many legal experts have said that principle does not apply to former presidents, and US President Joe Biden's administration has denied executive privilege to the former Trump aides.
Republicans lined up to object before the vote, accusing Democrats of waging a political war.
"Democrats are using the power of the federal government to jail their political opponents," House Republican leader Kevin McCarthy said.
"Today's resolution is all about criminalising dissent."
Mr McCarthy previously said that Mr Trump was responsible for the violence at the Capitol.
Contempt of Congress bears a penalty of up to a year's imprisonment and a fine up to $100,000.
The House backed contempt-of-Congress charges last year for Steve Bannon, an adviser to Mr Trump. Mr Bannon was charged in a case set to go to trial in July.
The chamber also voted in favour of a contempt charge for Mark Meadows, a former House member who became Mr Trump's chief of staff, but there has been no word from the Department of Justice on whether charges will be filed.
The Democratic-led select committee has been investigating events leading to the assault on the Capitol by thousands of Trump supporters on January 6, 2021, when then-vice president Mike Pence and legislators gathered to certify Mr Biden's victory in the November 2020 election.
Mobs rampaged through the Capitol, injuring police officers and sending Mr Pence, politicians, staff and journalists fleeing for safety, after Mr Trump repeated his false claims at a raucous rally that his defeat was the result of fraud.
Four people died on the day of the riot, and one Capitol Police officer who fought with rioters died the next day. Four officers have since taken their own lives.
Reuters contributed to this report