Several economists have reportedly left the Agriculture Department’s research branch, saying they’ve been retaliated against for publishing research that shows Trump administration policies hurt most farmers. According to Politico, six economists at the Economic Research Service (ERS) quit on a single day in late April in frustration over the alleged retaliation efforts and suspicions that Agriculture Secretary Sonny Perdue is attempting to change the research arm. Perdue reportedly announced that the ERS could be brought under the control of the USDA’s chief economist, who reports directly to him. The secretary also said the agency would be moving over 250 ERS positions out of Washington and to the heartland.

He reportedly ordered the economists to claim their research should not be “construed to represent any agency determination or policy”—which has been seen as a way to water-down the potency of their conclusions. “The administration didn’t appreciate some of our findings, so this is retaliation to harm the agency and send a message,” a current ERS employee told the website. Perdue’s office declined to comment on how many agency employees have left or respond to claims of “political interference in the research service.”