US senators has introduced a bipartisan measure that would protect the special prosecutor heading the Russia investigation, in a bid to check any attempt by President Donald Trump to fire him.
The bill faces long odds of making it into law, but it could serve as a serious warning to Trump not to sack the man investigating him.
The Special Counsel Independence and Integrity Act would ensure that Robert Mueller, who is also probing any Trump campaign contacts or coordination with Russia, and any future special counsels could only be fired for "good cause" by a senior Justice Department official.
Should the termination occur, the special counsel would have 10 days to challenge the firing in court.
The bill comes one day after the White House insisted that Trump has the power to fire Mueller.
Trump's attacks on Mueller have grown louder: on Wednesday he branded the Russia probe "fake" and "corrupt," blaming it for worsening ties between Washington and Moscow.
"We have faith in Mueller," said Republican Senate Foreign Relations Committee chairman Bob Corker.
“I've shared with the president that I think it would be a tremendous mistake on his part to fire him," Corker said, warning that "I think it would end his presidency as he knows it."