By Gabe Cohen, CNN(CNN) — The Trump administration has launched an internal investigation into FEMA employees who signed a public letter to Congress warning that the administration’s overhaul of the disaster relief agency is undermining emergency response and endangering the public. Of the more than 180 current and former FEMA staffers who signed the August letter, most did so anonymously. FEMA has not disclosed the total number of workers the agency placed on paid leave. The emails indicate that the inquiry is not a criminal investigation and direct the FEMA employees to contact investigators for more information. However, lawyers for the FEMA employees argue that the investigation is an intimidation tactic and likely constitutes illegal retaliation against the workers for exercising their first amendment and whistleblower rights.