Republican Sen. Lindsey Graham on Wednesday said Comey’s decision not to recommend charges against Clinton should be followed by a congressional investigation into her use of a private email server during her time as secretary of state.

The former FBI director made the request in a letter sent to the acting director of the FBI and to Attorney General Jeff Sessions, The Hill reported.

Graham wrote in the letter that he was “deeply troubled by the suggestion that Attorney General Sessions should be pressured to recuse himself from the investigation into Secretary Clinton’s email practices.”

Graham said he is asking Comey to respond to his letter by July 10.

“It is imperative that you address my concerns,” Graham wrote.

“We need a transparent, independent, and nonpartisan investigation into the matter.”

Graham’s request came on the heels of former Rep. Jason Chaffetz (R-Utah), a Trump supporter who has questioned Comey’s handling of the Hillary Clinton email probe.

Chaffetz called for a bipartisan probe into the FBI’s handling the Clinton probe and the FBI director’s decision to not recommend charges.

“There are some serious questions about the actions and the credibility of this director,” Chaffetz said.

“I would hope that he would step down and allow for the kind of independent and transparent investigation that is necessary.”