Just weeks ago, Gingrich had heaped praise on Mueller, hailing him as a "superb choice" for special counsel whose reputation was "impeccable for honesty and integrity".
"While the president has the right to, he has no intention to do so", Sanders told reporters aboard Air Force One while returning from a visit to Milwaukee, CNN reports. Senators on Tuesday questioned both Attorney General Jeff Sessions and Deputy Attorney General Rod Rosenstein on how the inquiry is being handled.
A number of key Republicans have publicly advised Trump to keep Mueller. Trump hasn't commented on the former Federal Bureau of Investigation director. "The best advice would be to let Robert Mueller do his job", he told reporters.
But expressions of discontent with Mueller are bubbling up nonetheless. If accurate, the report would also indicate Trump still has no understanding of the position the appointment of a special counsel has placed him in.
However, Adam Schiff, a Democrat member of the House Intelligence Committee Adam Schiff, said the House would not tolerate Trump firing Mueller.More news: Polanski's victim pleads to end case: 'He owes me nothing'
Trump advisors and conservative pundits including Newt Gingrich and Ann Coulter have called for Mueller's removal.
Peter Carr, a spokesman for Mueller, declined to comment on Ruddy's remarks.
Anxiety about the probe - and fresh concerns about the political leanings of some of the attorneys involved - is percolating in the West Wing of the White House. Trump viewed the issue as a "witch hunt", according to the Times. Congressman Paul Ryan, Speaker of the House of Representatives, said he has "confidence" in Mueller.
Still, it took until Tuesday night for the White House to actually dispute Ruddy's suspicion.More news: Terrorists attack security forces at six places in Kashmir valley with grenades
A spokesman for Trump's lawyer said "the Federal Bureau of Investigation leak of information regarding the President is outrageous, inexcusable and illegal". The person spoke on condition of anonymity to discuss private conversations.
The notion that Mueller, a 72-year-old former Federal Bureau of Investigation director who has spent decades in the highest levels of the US government, needs the special counsel gig badly enough to allow himself to be manipulated by Trump is laughable, but you have to remember that the president probably still believes that people live in genuine horror of him telling them "you're fired!" Trump's wife, Melania, has adopted a more temperate tone, telling her husband that she believed the appointment of Mueller would speed resolution of the Russian Federation scandal and expressing her view that he would be exonerated, according to two people with direct knowledge of her advice.
The special counsel overseeing the investigation into Russia's role in the 2016 election is interviewing senior intelligence officials as part of a widening probe that now includes an examination of whether President Trump attempted to obstruct justice, officials said.
But Stephen Gillers, a New York University professor who specializes in legal and judicial ethics, said the Mueller interview with Trump presented "no conflict whatsoever". "And there is no collusion between certainly myself and my campaign, but I can always speak for myself - and the Russians, zero", Trump responded. Still, Gingrich said any special counsel with an agenda can "all of the sudden find something procedural and technical to latch onto".
In 1973 President Richard Nixon ordered his attorney general to fire Archibald Cox, the special prosecutor who was leading the Watergate investigation. Sessions recused himself from investigations related to the Trump campaign in February, a move that also provoked Trump's ire.More news: UK prime minister's top aides resign after election fiasco