“The Environmental Protection Agency has a zero-tolerance policy for career bureaucrats unlawfully undermining, sabotaging, and undercutting the administration’s agenda as voted for by the great people of this country last November,” an EPA spokesperson said in a statement.

The letter was organized by Stand Up for Science, a group that planned a March rally in Washington to protest the Trump administration’s steep cuts to federally funded scientific research. Of the 278 E.P.A. employees who signed the letter, 173 signed their names, while 105 signed anonymously for fear of retaliation.