A top Democrat in the U.S. Congress has warned President Donald Trump against firing Special Counsel Robert Mueller or pardoning any targets of Mueller's probe into ties between Russia and Trump's election campaign.
Speaking on the Senate floor late on December 20, Senator Mark Warner, the top Democrat on the Senate Intelligence Committee, said that growing criticism of Mueller's probe by the White House and congressional Republicans suggests they are laying the groundwork for Mueller's removal or other interference in the investigation.
Warner warned that any attempt to remove Mueller "has the potential to provoke a constitutional crisis."
Trump has repeatedly denied he plans to fire Mueller, although he has asserted he has the power to do so.
While the U.S. law authorizing special counsels does not allow Trump to directly fire Mueller, critics say he could demand that top Justice Department officials dismiss Mueller and then remove them if they don't do so.
During the so-called "Saturday Night Massacre" in 1973, former President Richard Nixon demanded that his attorney general and deputy attorney general fire the Watergate scandal investigator, which they refused to do, resigning instead.
"Over the last several weeks, a growing chorus of irresponsible voices have called for President Trump to shut down Special Counsel Mueller's investigation," Warner said, adding that the calls were "seemingly coordinated."
"The president has said he's not considering removing Special Counsel Mueller, but the president's track record on this front is a source of concern," Warner said, noting that Trump unexpectedly fired former FBI Director James Comey, who was leading the Russia investigation earlier this year.
"I'm certain that most of my colleagues believed that he wouldn't fire Jim Comey," Warner said. Comey's dismissal in May led to a groundswell of support in Congress for the appointment of a special counsel, who cannot as easily be fired.
On the question of pardons, rumors have circulated in Washington that Trump might pardon targets of the investigation, including his former campaign chairman, Paul Manafort, who was indicted by Mueller, or his former national security adviser, Michael Flynn, who pled guilty to lying to the FBI and is now cooperating with Mueller's probe.
White House lawyers have repeatedly said the president is not considering any pardons.
But Republicans and close allies of Trump have recently ratcheted up attacks on Mueller and his team of investigators, charging them with bias and pushing for counterinvestigations into matters they say should have greater priority at the Justice Department.
Republican members of the House Judiciary Committee last week lambasted Deputy Attorney General Rod Rosenstein, who appointed Mueller as special counsel, after the disclosure that a top FBI agent on Mueller's investigative team wrote text messages disparaging Trump and praising his Democratic opponent, Hillary Clinton.
Mueller dismissed the agent after the texts came to light.
Although Mueller's appointment initally had bipartisan support in Congress, Warner said Republicans have grown increasingly hostile to the probe.
He cited a recent Fox News interview with senior Trump adviser Kellyanne Conway, who said the "fix was in" against Trump as the right-leaning television network posted an on-screen graphic saying "Coup in America?"
Still, most Republicans in Congress have not called for Mueller's dismissal, AP reported, and many Republicans continue to urge against intervention in his investigation.
"I remain convinced that when this is all said and done, Mueller is going to only pursue things that are true, and he will do it in a fair and balanced way," said Senator Marco Rubio, a Republican on the Senate Intelligence Committee,
With reporting by AP and Reuters