The EPA is placing 144 officials on leave effective immediately after they signed on to a public letter excoriating the agency's energy dominance agenda and direction under the Trump administration.

EPA administrator Lee Zeldin said the action was part of a zero tolerance policy for employees who seek to undermine the agency's policies. Zeldin emphasized that the majority of EPA employees are dedicated to implementing the Trump EPA's agenda and that the letter represented the views of a small minority.

The officials will remain on leave pending further investigation, according to the EPA.

Zeldin's drastic action Thursday sends a clear message to EPA staffers that the administration will not be pressured by such public letters and that it will pursue its agenda regardless of such dissent. The sprawling agency employs more than 15,000 officials across the country and it has historically proven difficult for Republican administrations to keep its left-leaning staff in line.

"We have a ZERO tolerance policy for agency bureaucrats unlawfully undermining, sabotaging, and undercutting the agenda of this administration as voted for by the great people of this country last November," Zeldin said in a statement. "The will of the American public will not be ignored at our agency."

"Unfortunately, a small number of employees signed onto a public letter, written as agency employees, using their official work title, that was riddled with misinformation regarding agency business," he added. "Our ZERO tolerance policy is in full force and effect and will be unapologetically implemented unconditionally."

The officials sent the letter to Zeldin earlier this week, outlining their dissent with his actions and accusing him of unraveling environmental protections.

The letter listed five primary concerns with the Trump EPA. According to the officials, the agency is undermining public trust, ignoring science, gutting environmental justice initiatives, dismantling the Office of Research and Development, and promoting a "culture of fear."

"EPA employees join in solidarity with employees across the federal government in opposing this administration's policies," the letter stated.

The 144 officials placed on leave Thursday are the only individuals identified as active EPA employees—in total, more than 400 current and former government officials signed onto the letter, though the bulk of the signatories work at other agencies, used pseudonyms, are retired, or are former Democratic political appointees.

Since taking the position, Zeldin has prioritized weeding out wasteful green spending programs introduced during the Biden administration and has rolled back a series of environmental regulations he said are overburdensome and hurt economic growth. Climate activists and Democrats have criticized the actions, arguing in favor of more regulations to curb greenhouse gas emissions.