The number two Senate Republican said it would be a bad idea for the Trump administration to fire special counsel Robert Mueller.

ABC News Chief Anchor George Stephanopoulos asked Sen. John Cornyn of Texas on “This Week” Sunday about reports that allies of President Donald Trump are laying the groundwork for the firing of Mueller, who is investigating alleged Russian interference in the 2016 U.S. presidential election and possible collusion with Trump associates.

Cornyn responded, “I read that the president’s own lawyer says that’s not going to happen. I think that would be a mistake, myself.”

The Texas senator added that Mueller should make sure that FBI agents and prosecutors on his team are completely unbiased. A senior FBI agent was removed from Mueller’s team after repeatedly calling Trump an “idiot” in text messages.

“There are plenty of FBI agents and prosecutors who have not been politically involved on behalf of Democrats or overtly critical who can serve in this important investigation,” Cornyn said. “I have confidence in Director Mueller, I just think that he would be concerned about the appearance of conflicts of interest that would undermine the integrity of the investigation.”