Senate Minority Leader Chuck Schumer, D-N.Y., called Monday for the Senate to hold brief sessions throughout August in order to keep the Senate out of recess and prevent President Trump from making a recess appointment to replace Attorney General Jeff Sessions.

Democrats charge that Trump's recent comments about his "beleaguered" attorney general show he wants to fire Sessions in order to fire special counsel Robert Mueller, who is investigating Trump's alleged ties to Russia.

"It also raises questions about whether the president wants the attorney general to resign so he can appoint a new attorney general willing to fire special counsel Mueller," Schumer said. "If such a scenario were to pass, we would have a constitutional crisis on our hands."

"The Senate should remove even the possibility of it coming about," Schumer said. "So in the tradition of the Senate, I expect we will hold pro forma sessions throughout the upcoming recess to prevent a recess appointment from being made."

"The fact that President Trump continues to meddle with the Department of Justice and impede the investigation gets to a larger question — if President Trump has nothing to hide, nothing to fear, why not let special counsel Mueller do his job, follow the facts, and finally get to the bottom of the matter?" he said.

Pro forma sessions are conducted to comply with the Constitution, which states that neither or the Senate or the House "can adjourn for more than three days without the consent of the other." In the last few years, they have been used to block potential recess appointments by the executive branch.

In 2014, the Supreme Court ruled that former President Barack Obama improperly made an appointment to the National Labor Relations Board and overreached his executive authority while the Senate was holding pro forma sessions in early 2012.