Sen. Josh Hawley said that he will block quick confirmation of President-elect Joe Biden’s pick for homeland security secretary, Alejandro Mayorkas.

Hawley’s move is likely to enrage the Missouri senator’s colleagues in the chamber further, some of whom have called for Hawley to be expelled from the Senate over his objection to certifying Electoral College results from Pennsylvania even after the Jan. 6 siege on the U.S. Capitol building.