President Trump unleashed another blistering attack Tuesday on Robert S. Mueller III, calling the special counsel investigating Russian election interference a “conflicted prosecutor gone rogue” who is doing “TREMENDOUS damage” to the criminal justice system.

In morning tweets, Trump employed some of his harshest language to date in a continuing attempt to discredit Mueller as he probes possible coordination between Russia and Trump’s 2016 campaign and whether Trump has obstructed the investigation.

“Wait until it comes out how horribly & viciously they are treating people, ruining lives for them refusing to lie,” Trump said. “Mueller is a conflicted prosecutor gone rogue. . . . The Fake News Media builds Bob Mueller up as a Saint, when in actuality he is the exact opposite. He is doing TREMENDOUS damage to our Criminal Justice System.”

Trump also repeated a complaint that Mueller is not looking into the president’s political adversaries.

In a briefing for reporters later Tuesday, White House press secretary Sarah Sanders said that Trump has “no intent” of getting rid of Mueller despite the tone of his tweets and that she was not aware of any discussions of Trump pardoning people whose lives he said were ruined.

Sanders also reiterated the White House’s view that Mueller’s investigation should come to a close and insisted that Trump has nothing to fear from a report Mueller is preparing on his findings.

“I don’t think the president has any concerns about the report because he knows there was no wrongdoing by him and he knows there was no collusion,” she said.

Meanwhile, Senate Majority Leader Mitch McConnell (R-Ky.) told reporters Tuesday that he has no plans to bring to the floor a bill that would protect Mueller from being fired. Sen. Jeff Flake (R-Ariz.), an outspoken critic of Trump, has said that he will not vote for any of the president’s judicial nominees until the Senate votes on the measure.

“This is a solution in search of a problem,” McConnell said. “The president is not going to fire Robert Mueller. ... We have a lot of things to do to try to finish up this year without taking votes on things that are completely irrelevant to outcomes.”

Trump’s tweets followed several high-profile developments Monday in the investigation by Mueller.

Prosecutors working with Mueller said Paul Manafort, Trump’s former campaign chairman, had breached a plea agreement, accusing him of lying repeatedly to them in the investigation into Russian interference. In a court filing, Manafort denied doing so intentionally.

Also Monday, conservative author Jerome Corsi said he had rejected a deal offered by Mueller to plead guilty to one count of perjury because he would have been forced to say untruthfully that he intentionally lied to investigators.

Corsi provided research during the 2016 campaign to Roger Stone, a longtime adviser to Trump. For months, the special counsel has been scrutinizing Stone’s activities to determine whether he coordinated with WikiLeaks or its founder, Julian Assange, in the release of hacked Democratic emails during the campaign. Stone and WikiLeaks have repeatedly denied any such coordination.

In another development Monday, one of Trump’s former aides, foreign policy adviser George Papadopoulos, reported to prison after a federal judge rejected a bid to delay the start of his sentence while a constitutional challenge to Mueller’s investigation remains unresolved.

Papadopoulos pleaded guilty to lying to the FBI about Russian contacts during the 2016 campaign. But in recent weeks, he has hired a new legal team and complained publicly that he was framed by intelligence agencies looking to smear Trump’s campaign.

Mueller’s 18-month-old investigation has led to charges against 32 people, including 26 Russians. Four aides to Trump have pleaded guilty to various charges, most recently Manafort in September.

Tuesday was the second day in a row that Trump has employed his Twitter account to attack Mueller.

On Monday morning, Trump sought to cast doubts about the special counsel’s expected report, questioning why his team has not spoken with “hundreds of people” who saw no evidence of coordination with Russians during the 2016 campaign.

Trump also again accused Mueller of having conflicts of interest, which he did not describe, and suggested that his report should include recommendations about unspecified “crimes of many kinds” committed by Trump’s adversaries.

The stepped-up attacks on Mueller come the week after Trump submitted answers to the special counsel about his knowledge of Russian interference in the 2016 election. Before doing so, Trump told reporters that he had answered the questions “very easily.”

In this week’s tweets, Trump has not spelled out why he considers Mueller to be “conflicted.” But aides have pointed in the past to an alleged dispute over membership fees at Trump National Golf Club in Northern Virginia.

Last year, two White House advisers told The Washington Post that Mueller had a dispute over membership fees when he resigned as a club member in 2011. A spokesman for Mueller, who was FBI director at the time, said there was no dispute when Mueller left the club.

In the past, Trump has also cited the fact that Mueller had served as FBI director under President Barack Obama.

A registered Republican, Mueller was nominated to the post in 2001 by President George W. Bush. In 2011, Obama gave Mueller’s original 10-year term a two-year extension.

Mueller was tapped to be special counsel last year by Deputy Attorney General Rod J. Rosenstein, a Republican appointee in the Trump administration.

Felicia Sonmez, Devlin Barrett, Rosalind S. Helderman, Spencer S. Hsu, Rachel Weiner and Matt Zapotosky contributed to this report.