US Democrats plan to introduce misconduct charges that could lead to a second impeachment of President Donald Trump, two sources familiar with the matter say.
The move comes after a violent crowd of Trump supporters stormed the US Capitol in an assault on American democracy.
With a majority in the House of Representatives, Democrats appear poised for a historic first: No president has ever been impeached twice.
But it is unclear whether lawmakers would be able to remove Trump from office, as any impeachment would prompt a trial in the Senate, where his fellow Republicans still hold power.
Top Democrats have called on Vice President Mike Pence and Trump's Cabinet to invoke the US Constitution's 25th Amendment, which allows them to remove the president if he is unable to discharge his official duties.
Pence is opposed to the idea, an adviser said.
Democrats, who said a House vote on impeachment could come next week, hope the threat could intensify pressure on Pence and the Cabinet to act to remove Trump before his term ends in less than two weeks.
The sources said the articles of impeachment, which are formal charges of misconduct, were crafted by Democratic Representatives David Cicilline, Ted Lieu and Jamie Raskin.
Lieu said on Twitter the draft had 150 co-sponsors.
A copy circulating among members of Congress charges Trump with "inciting violence against the government of the United States" in a bid to overturn his loss to President-elect Joe Biden in the 2020 presidential election.
The articles also cite Trump's hour-long phone call last week with Georgia Secretary of State Brad Raffensperger, in which Trump asked the official to "find" enough votes to overturn Biden's victory in that state.
Leaving the Capitol after a more than three-hour conference call with House Democrats, Speaker Nancy Pelosi told reporters that "our conversation continues".
"We have several options so far" on potentially removing Trump from office, Pelosi said.
The extraordinary developments came two days after Trump exhorted thousands of followers to march to the Capitol, prompting a chaotic scene in which crowds breached the building, forced the evacuation of both chambers and left a police officer and four others dead in their wake.
Senator Ben Sasse of Nebraska said he would consider supporting an impeachment proceeding.
Republican Senator Lisa Murkowski said Trump should resign immediately and that if the party cannot separate itself from him, she is not certain she has a future with it.
"I want him to resign. I want him out. He has caused enough damage," the Alaska Senator told the Anchorage Daily News.
Trump allies including Senator Lindsey Graham and the House Republican leader Kevin McCarthy have urged Democrats to shelve talk of impeachment to avoid further division.
If the House impeaches Trump, the decision on whether to remove him would fall to the Republican-controlled Senate, which has already acquitted him once before.
With Trump's term ending a day after the Senate is scheduled to return from recess on January 19, the chances of an actual ouster appear slim.
Biden told reporters on Friday he viewed Trump as "unfit" for office but said he would let Congress decide for itself what to do.