(CNN) President Donald Trump convened a heated meeting in the Oval Office on Friday, including lawyer Sidney Powell and her client, former national security adviser Michael Flynn, two people familiar with the matter said, describing a session that began as an impromptu gathering but devolved and eventually broke out into screaming matches at certain points as some of Trump's aides pushed back on Powell and Flynn's more outrageous suggestions about overturning the election.
Flynn had suggested earlier this week that Trump could invoke martial law as part of his efforts to overturn the election that he lost to President-elect Joe Biden -- an idea that arose again during the meeting in the Oval Office, one of the people said. It wasn't clear whether Trump endorsed the idea, but others in the room forcefully pushed back and shot it down.
The meeting was first reported by the New York Times.
White House aides who participated in the meeting, including White House chief of staff Mark Meadows and counsel Pat Cipollone, also pushed back intensely on the suggestion of naming Powell as a special counsel to investigate voter fraud allegations Trump's own administration has dismissed (or, as seems more feasible, hiring her in the administration for some kind of investigatory role). Powell has focused her conspiracies on voting machines and has floated the notion of having a special counsel inspect the machines for flaws.
Another idea floated in the meeting was an executive order that would permit the government to access voting machines to inspect them.
One person described the meeting as "ugly" as Powell and Flynn accused others of abandoning the President as he works to overturn the results of the election.
"It was heated -- people were really fighting it out in the Oval, really forceful about it," one of the sources said.
One of the sources described an escalating sense of concern among Trump's aides, even those who have weathered his previous controversies, about what steps he might take next as his term comes to an end.
Shortly after that meeting, Trump's campaign staff received a memo from the campaign legal team on Saturday instructing them to preserve all documents related to Dominion Voting Systems and Powell in anticipation of potential litigation by the company against the pro-Trump attorney.
The memo, viewed by CNN, references a letter Dominion sent to Powell this week demanding she publicly retract her accusations and instructs campaign staff not to alter, destroy or discard records that could be relevant.
A serious internal divide has formed within Trump's campaign following the election with tensions at their highest between the campaign's general counsel, Matt Morgan, who sent the memo Saturday, and Trump lawyer Rudy Giuliani.
Giuliani had called the Department of Homeland Security's Ken Cuccinelli and asked if it was possible for DHS to seize voting machines, according to two sources familiar with the call. Cuccinelli, the senior official performing the duties of the DHS deputy secretary, told Giuliani it wasn't within the authority of the department's cybersecurity agency to seize voting machines, according to one of the sources, who said the call took place Thursday. The call was first reported by the New York Times.
Though the campaign once distanced itself from Powell, Trump has been urging other people to fight like she has, according to multiple people familiar with his remarks. He has asked for more people making her arguments, which are often baseless and filled with conspiracy theories, on television.
CNN spotted Powell leaving the residence side of the White House shortly before 9 p.m. ET Sunday.
Powell denied that she was meeting with Trump, but when pressed again as to whether she met with the President or other White House officials, Powell retorted: "It would be none of your business."
This story has been Sunday updated with additional reporting.