US Senator Lindsey Graham has vowed to "get to the bottom" of allegations that discussions were held in 2017 on the possibility of removing President Donald Trump from office.
The Republican senator, who's chairman of the powerful Senate Judiciary Committee, was responding to comments made by former acting FBI chief Andrew McCabe.
Mr McCabe told CBS' 60 Minutes that deputy US attorney general Rod Rosenstein discussed the numbers needed to invoke the 25th Amendment.
The amendment, which has never been invoked, empowers a majority of US cabinet members to remove a president if deemed unfit for office.
It was allegedly brought up by Mr Rosenstein after Donald Trump fired FBI director James Comey.
'Very concerned about the president'
In the interview, Mr McCabe explained: "The discussion of the 25th Amendment was simply... Rod raised the issue and discussed it with me in the context of thinking about how many other cabinet officials might support such an effort.
"The deputy attorney general was definitely very concerned about the president, about his capacity and about his intent at that point in time."
60 Minutes Moment of the Week: Former FBI acting director McCabe says Deputy Attorney General Rod Rosenstein raised the idea of removing President Trump via the 25th Amendment. https://t.co/wkC4AKxGiC pic.twitter.com/UkOb4QbrZh
— 60 Minutes (@60Minutes) February 18, 2019
He added that the conversation happened at an "unbelievably stressful time", and the idea was simply 'thrown out' during 'frenzied, chaotic' conversations about the next steps.
The New York Times has previously reported that Mr Rosenstein discussed the amendment, as well as the possibility of secretly recording President Trump.
At the time, the deputy attorney general dismissed the report as "inaccurate and factually incorrect".
'We will have a hearing about who's telling the truth'
Responding to Mr McCabe's comments, Senator Graham said he was 'floored' by the assertions.
He suggested that the former acting FBI chief's remarks should be taken with a 'grain of salt' as he's currently promoting a book.
However, Graham pledged to hold hearings on the issue.
He told CBS' Face The Nation programme:
"The deputy attorney general denies it. So I promise your viewers the following, that we will have a hearing about who's telling the truth, what actually happened.
"I'm going to do everything I can to get to the bottom of the Department of Justice FBI behavior toward President Trump and his campaign."
