WASHINGTON — The top Democrat on the Senate Intelligence Committee warned President Donald Trump against firing special counsel Robert Mueller or pardoning any targets of the federal probe into Russia and the president’s Republican campaign.

In a speech from the Senate floor, Virginia Sen. Mark Warner said Wednesday that growing criticism of Mueller’s probe pointed to an effort to lay the groundwork for Mueller’s removal or other interference in the federal investigation. Warner said any attempt to remove Mueller would provoke a “constitutional crisis.”

Asked this past weekend if he was considering trying to push out Mueller, Trump replied, “No, I’m not.” And a White House lawyer has repeatedly said the president is not considering any pardons. Trump cannot directly fire Mueller, but critics say he could demand that top Justice Department officials fire Mueller and then remove them if they don’t follow through.

Many Republicans, including Warner’s colleagues on the Senate’s Russia probe, have urged a hands-off approach to Mueller.

“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. “I’m certain that most of my colleagues believed that he wouldn’t fire (former FBI Director) Jim Comey.”

Warner’s comments come as some Republicans and close allies of Trump have ratcheted up their critiques of Mueller and his team of investigators. Republican members of the House Judiciary Committee tore into Deputy Attorney General Rod Rosenstein, who appointed Mueller as special counsel, after it was revealed that a top FBI agent on the investigation wrote text messages disparaging Trump and praising his Democratic opponent, Hillary Clinton.

Warner cited a recent Fox News report that featured senior Trump adviser Kellyanne Conway saying the “fix was in” against Trump and that included an on-screen graphic that said “Coup in America?”

But Trump’s supporters have largely stopped shy of calling for Mueller’s firing.

Rather, many Republicans, including Warner’s colleagues on the Senate’s Russia probe, have urged a hands-off approach to Mueller.

“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 Sen. Marco Rubio, a Florida Republican on the Senate Intelligence Committee.

Associated Press writer Kevin Freking contributed to this report.