Attorney General Loretta Lynch must drop all efforts to prosecute climate change skeptics or risk engaging in “prosecutorial misconduct,” a group of Senate Judiciary Committee members warned.

“As you well know, initiating criminal prosecution for a private entity’s opinions on climate change is a blatant violation of the First Amendment and an abuse of power that rises to the level of prosecutorial misconduct,” five lawmakers wrote to Lynch on Wednesday. Signatories were Sens. Mike Lee, R-Utah, Ted Cruz, R-Texas, David Perdue, R-Ga., Jeff Sessions, R-Ala., and David Vitter, R-La.