FBI employees fired for their roles in the investigation of President Donald Trump’s retention of classified documents at his Florida estate sued on Thursday to get their jobs back, calling their terminations unlawful acts of “political retribution.”

The complaint adds to the growing list of legal challenges to the mass terminations under FBI Director Kash Patel of agents who participated in investigations of the Republican president or are seen as opposed to Trump administration interests.

The suit was filed in federal court in Washington on behalf of nine agents, intelligence analysts and staff operations specialists who were fired in February following earlier dismissals of agents who had worked on the investigation into Trump’s efforts to overturn his 2020 presidential election loss to Democrat Joe Biden.