The US House committee investigating the January 6 attack on the Capitol on Thursday voted unanimously to subpoena Donald Trump, in the most aggressive action the panel has taken since it began its investigation last year.
Committee chair Bennie Thompson said the committee had an obligation to hear testimony from Mr Trump and that the former president "must be held accountable".
"We have left no doubt now that Donald Trump led an effort to upend American democracy that directly resulted in the violence of January 6," Mr Thompson said before the vote.
The vote came at the end of what could be the panel's final hearing before it releases a report of its findings.
"We also recognise that a subpoena to a former president is a serious and extraordinary action," Mr Thompson said.
"That’s why we want to take this step in full view of the American people, especially because the subject matter issue is so important."
But the subpoena will probably be met with defiance by Mr Trump, who is known to litigate investigative matters.
Should he defy his subpoena, the committee would have to decide whether to hold a House vote to hold him in contempt of Congress.
During its hearing, the panel told how Mr Trump was central to a multi-part plan to overturn the 2020 election in what amounted to a “staggering betrayal” of his oath of office.
“It's still hard to believe,” Mr Thompson said.
January 6 Committee votes to subpoena former president Donald Trump
He and co-chair Liz Cheney said the former president had acted in a “substantial” and “premeditated” way in the events leading up to, and on the day of, January 6.
“None of this would have happened without him. He was personally and substantially involved in all of it,” Ms Cheney said.
Meanwhile, the former president took to social media to again perpetuate voter fraud claims.
"The Unselect Committee knowingly failed to examine the massive voter fraud which took place during the 2020 Presidential Election — the reason for what took place on January 6" Mr Trump said on his Truth social account on Thursday.
New footage provided by the panel showed members of Congress hiding in an undisclosed location while Capitol police were being overrun by the mob.
“And all at the instigation of the president the United States,” footage captured House Speaker Nancy Pelosi saying as she looked at a television screen showing protesters breaking the windows of the Capitol.
Video shows Nancy Pelosi took charge during January 6 attack
The committee also presented new evidence it had obtained from the Secret Service, revealing that the agency was aware of plans to attack the Capitol.
Congressman Adam Schiff said the committee has received nearly 1 million emails and other records from Secret Service officials.
Those included emails that warned protesters were “armed and ready” and “their plan is to literally kill people”.
In the months leading up to the attack, Mr Trump ignored advice from White House officials that his claims of fraud were false.
Instead he relentlessly repeated them to convince tens of millions of voters that he won the election.
The committee said the January 6 insurrection was not just a historic event, but also a warning on the fragility of American institutions.
“Why would Americans assume that our Constitution and our institutions in our republic are invulnerable to another attack? Why would we assume that those institutions will not fall next time?” Ms Cheney asked.
Recent polls suggest that Mr Trump's grip on the party still remains strong, despite his repeated lies.
Nearly one third of Republican statewide candidates on ballots — who would oversee election protocols — supported overturning the results of the 2020 election, an AP poll found.
Another analysis conducted by The Washington Post found that nearly half of Republican candidates looking to hold state and federal offices have denied or questioned the outcome of the 2020 election.
Mr Thompson said the committee's work was not politically motivated, noting that the panel has asked viewers to follow the hearings with an open mind and “to let the facts speak for themselves before reaching any judgment”.
But with Republicans expected to control the House of Representatives next year and shut down the January 6 committee's investigation, its members are on a tight deadline to submit a report on their findings.
An interim report could come before the midterm elections on November 8, Mr Thompson said, which would probably fuel the growing polarisation that races across the country have taken.
The panel is still hurrying to complete its final report by the end of the year.
