The Trump administration is facing a lawsuit from a major federal employee union over a recently issued executive order that strips some protections from the civil service.

The National Treasury Employees Union (NTEU), which represents 150,000 employees across 33 federal agencies, said the order signed by President Trump last week makes “political loyalty — not merit or skill — a prerequisite of the job.”

The order deals only with career employees that work on policy matters, making it easier to hire employees outside of the competitive process while allowing them to be fired “at will” with little recourse.

“The president has ordered agency leaders to identify which employees should be forced to lose the civil service protections they are entitled to under the law, allowing them to be hired or fired at will for purely partisan reasons,” the NTEU said in a release.

The suit asks courts to block the executive order, arguing that Trump is bypassing a congressional role.

Federal law does allow the president to make changes to civil service laws when necessary, but the NTEU argues the White House has failed to supply any data to justify Trump's order.

The order claims “agencies need the flexibility to expeditiously remove poorly performing employees from these positions without facing extensive delays or litigation.” It gives agencies 90 days to determine which employees should be slotted into the new Schedule F positions.

The White House did not immediately respond to a request for comment on the lawsuit.

Critics fear the order could be used to suppress work in public health, the environment and defense, where government experts’ work has at times conflicted with administration goals.

Though civil service protections are often compared to tenure for professors, they are similar to processes in place at private companies, where employees must be notified of performance issues and given a chance to improve before being dismissed.

“This is not solving some problem of ‘you can’t get rid of federal employees.’ You can. If people aren't really performing you can get rid of them. Trust me, I’ve done it,” Andrew Rosenberg with the Union of Concerned Scientists, who previously served as deputy director for fisheries at the National Oceanic and Atmospheric Administration, told The Hill when the order was first released. He said the government should have to follow fair labor laws.

Trump’s order has already pushed one top appointee to the panel that advises the government on employee compensation to resign.

Ronald Sanders, a Republican who has served under administrations of both parties, said he could not continue as chair of the Federal Salary Council when the president’s new order “seeks to make loyalty to him the litmus test for many thousands of career civil servants.”

The federal workforce used to be based on a political patronage system, with positions awarded to those who had given political or financial support. 

That changed in the 1880s when lawmakers passed the Pendleton Civil Service Reform Act, which requires federal positions to be filled based on merit.

“It is shocking that after four years, the Trump administration still doesn’t understand that the United States expressly rejected a spoils system 137 years ago because it was ripe for corruption,” NTEU President Tony Reardon said in a statement. 

“As with previous Trump executive orders and our legal challenges to them, we intend to remind this administration that the taxpayers are better served by federal employees who swear an oath to the Constitution, not a president.”