Story highlights "To have a President say that, that is not normal," Flake said

Flake also said Congress should work to ban bump stocks if agencies don't take action

Washington (CNN) Sen. Jeff Flake criticized President Donald Trump for encouraging the Department of Justice and the FBI to investigate his political opponents, telling CNN's "New Day" on Monday it isn't "normal" presidential behavior.

"A lot of people are concerned about where we're going ... the vitriol that we now see daily, the kind of behavior that the President has exhibited, saying over the weekend, or on Friday, saying the FBI should go after the President's political adversaries," said the Arizona Republican, who has emerged as a fervent Trump critic. "To have a President say that, that is not normal and we shouldn't accept it as normal."

After Justice Department special counsel Robert Mueller's investigation handed down indictments against his former campaign hands , both of whom have pleaded not guilty, the President lamented last week that he couldn't influence the DOJ and FBI to direct its efforts toward investigating Hillary Clinton, his 2016 general election opponent. The President's suggestion that his Justice Department target his political opponent is a call he's made before

Several other Republican critics of Trump have criticized the President for pressuring the FBI and DOJ to investigate his opponents.

Sen. Bob Corker, R-Tennessee, said in a statement Friday that "President Trump's pressuring of the Justice Department and FBI to pursue cases against his adversaries and calling for punishment before trials take place are totally inappropriate and not only undermine our justice system but erode the American people's confidence in our institutions."

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