Sen. Lindsey Graham warned President Donald Trump on Thursday against firing his attorney general — the latest Republican to try to deter Trump from a move that would carry huge consequences for the U.S. government.

"If Jeff Sessions is fired, there will be holy hell to pay," the Republican from South Carolina told reporters, according to video taken by NBC News.

A push to fire Sessions — who enraged Trump by recusing himself from the investigation into Russian efforts to influence the 2016 election and whether the Trump campaign colluded with the Kremlin — is seen as a possible precursor to removing the special counsel overseeing that probe. Graham also warned of consequences if the Trump administration tries to remove special counsel Robert Mueller, the former FBI director.

"Any effort to go after Mueller could be the beginning of the end of the Trump presidency, unless Mueller did something wrong. Right now, I have no reason to believe that Mueller is compromised," Graham said.

NBC News: WATCH: Sen. Lindsey Graham says there will be "holy hell to pay" if AG Jeff Sessions is fired. Video via @VaughnHillyard

Trump has publicly lambasted Sessions several times recently, and his anger stems from the attorney general's March recusal. Reports have said Trump has talked privately about replacing Sessions, potentially circumventing Congress by making an appointment while the Senate is in recess.

It is unclear how serious Trump is about appointing a new attorney general.

On Wednesday night, Senate Judiciary Committee Chairman Chuck Grassley, R-Iowa, said "no way" would he fit in confirmation of a new attorney general this year.

Graham said Thursday that he is working on bipartisan legislation to protect Mueller.