(CNN) - Democrats are vowing to investigate whether President Donald Trump obstructed justice -- with some openly floating the prospect of impeachment or his resignation -- following a bombshell BuzzFeed report that Trump personally directed his former attorney Michael Cohen to lie to Congress.
"We know that the President has engaged in a long pattern of obstruction. Directing a subordinate to lie to Congress is a federal crime. The @HouseJudiciary Committee's job is to get to the bottom of it, and we will do that work," New York Democratic Rep. Jerry Nadler, the chairman of the House Judiciary Committee, whose panel would lead potential impeachment proceedings, tweeted Friday.
Citing law enforcement officials, BuzzFeed reported Thursday night that Trump directed Cohen to claim negotiations to build a Trump Tower in Moscow ended months earlier than they actually did. Cohen confirmed to special counsel Robert Mueller's team that Trump issued the order to lie to Congress, BuzzFeed reported.
Late Friday, Mueller's office disputed the BuzzFeed report as "not accurate."
"BuzzFeed's description of specific statements to the Special Counsel's Office, and characterization of documents and testimony obtained by this office, regarding Michael Cohen's Congressional testimony are not accurate," said special counsel spokesman Peter Carr in a statement.
It's highly unusual for the special counsel's office to provide a statement to the media -- outside of court filings and judicial hearings -- about any of its ongoing investigative activities.
CNN has not corroborated the BuzzFeed report, which immediately raised questions about whether the President obstructed justice -- which could be a central charge in any potential impeachment proceedings. Asked for comment in response to the report, both the White House and Trump's attorney Rudy Giuliani said Cohen had no credibility, with Giuliani saying, "If you believe Cohen I can get you a great deal on the Brooklyn Bridge."
Democrats quickly took to social media and television to signal alarm about the report soon after it was published.
House Intelligence Chairman Rep. Adam Schiff -- who has promised to revive his panel's investigation into Russia and Trump despite the then-Republican-led committee's decision last year to end its probe -- said "we will do what's necessary to find out if it's true."
"The allegation that the President of the United States may have suborned perjury before our committee in an effort to curtail the investigation and cover up his business dealings with Russia is among the most serious to date," the California Democrat wrote on Twitter.
Eric Holder, the former attorney general under President Barack Obama, also called for Congress to begin impeachment proceedings if the report was corroborated. He said that Trump's attorney general nominee, William Barr -- who, if confirmed, would have oversight of the Mueller investigation -- must "refer, at a minimum, the relevant portions of material discovered by Mueller."
During his Senate confirmation hearing Tuesday, Barr, in an exchange with Sen. Lindsey Graham, R-South Carolina, said an effort by a president to "coach somebody not to testify or testify falsely" would constitute obstruction of justice.
Sen. Sheldon Whitehouse, a Rhode Island Democrat who sits on the Republican-controlled Senate Judiciary Committee, said that the BuzzFeed report, if accurate, would require a court review of the administration's long-held position that a sitting president cannot be indicted.
"If this is true, this is plain, slam-dunk, criminal obstruction of justice (18 U.S.C. 1505, 1512), subornation of perjury (18 U.S.C. 1622), conspiracy (18 U.S.C. 371) and likely aiding and abetting perjury (18 U.S.C. 2)," he added on Twitter Friday morning.
Rep. Joaquin Castro, a Texas Democrat on the House Intelligence Committee, said "President Trump must resign or be impeached" if the report is true.
And Rep. David Cicilline of Rhode Island, who sits on the House Democratic leadership team and the House Judiciary Committee, called the claim that Trump suborned perjury the "most serious threat to the Trump presidency we have seen so far."
"It's still my preference that we await the final report of Mr. Mueller," he told CNN's John Berman on "New Day" Friday. "But it becomes increasingly difficult when faced with evidence such as this. The Judiciary Committee certainly has a responsibility to begin hearing to really understand precisely what happened."