White House budget director Russell Vought said reductions-in-force were underway.

The Trump administration moved to begin laying off federal workers Friday while the government was shuttered, fulfilling threats from President Donald Trump to take advantage of the closure to shave off still more parts of the federal workforce he dislikes.

“The RIFs have begun,” White House budget director Russell Vought posted on X Friday afternoon, using an acronym for reductions-in-force.

A White House official, speaking on the condition of anonymity to discuss the plans, confirmed that the RIFs were starting, and said “they will be substantial.” The White House did not provide specifics on how many employees were affected, or at which departments.

The shutdown layoffs are the culmination of years of groundwork laid by Vought, an architect of the Project 2025 playbook for Trump’s second term, which outlined a drastically reduced federal bureaucracy. Vought’s office had threatened mass dismissals during the shutdown, perhaps even stretching into the hundreds of thousands, and told agencies they should “retain the minimal number of employees necessary.” Trump told reporters before the shutdown that he might fire “a lot” of people, and once the shutdown began, Vice President JD Vance and White House press secretary Karoline Leavitt indicated that cuts were coming, as well.

The Washington Post previously reported that the dismissals were likely to total fewer than 16,000.

The layoffs run counter to recent internal warnings from senior government officials that such dismissals are legally questionable. In the first days of the shutdown, officials privately counseled agencies against conducting reductions in force, or RIFs, while the government lacks funding, because it would likely violate the law, The Post reported this month.

The officials cautioned that the Antideficiency Act forbids the government from obligating or expending any money not appropriated by Congress, which means the government cannot incur new expenses during a shutdown, when funding has lapsed. The RIF process, which is extensive and involves promising severance payments, would probably be prohibited under the act, the officials concluded.

That theory will now almost certainly be put to the test. Even before the layoffs began, they drew a legal challenge from several federal unions. Their lawsuit, brought against OMB and the Office of Personnel Management on Sept. 30 over threats of dismissals, argued that the administration has no authority or ability to conduct RIFs amid a shutdown, in part citing the Antideficiency Act.

“Nothing in the Antideficiency Act or any other statute authorizes RIFs of employees who work in agencies or programs with a lapse in funding,” the suit said. “Ignoring binding federal law is arbitrary and capricious.”

Federal employment lawyers also said the attempted dismissals are almost certainly illegal, violating rules that guide the process of federal staff cutbacks. Federal regulations say that agencies can dismiss employees for one of several reasons, including a lack of work, a reorganization or a shortage of funds.

But a shutdown-driven temporary lapse in funding does not count as a shortage of funds, the lawyers said.

“It’s like trying to call an apple an orange — they’re both fruit but it’s not the same thing,” said Kevin Owen, a partner at a firm representing federal workers.

This round of layoffs is the latest development in a difficult year for federal workers, who have already seen hundreds of thousands of their co-workers depart through firings, retirement programs and a deferred resignation offer developed by the Trump administration. The last initiative alone saw 150,000 people leave federal service.

“In a year already filled with cruel and relentless attacks on the federal workforce, this is yet another example of this administration treating us like pawns and further dehumanizing and traumatizing us,” said an Environmental Protection Agency worker.

Despite early promises to fire many federal workers, administration officials had been largely moving away from mass layoffs after thousands took buyout offers and retired. For instance, Veterans Affairs, the second-largest federal agency, canceled an expected 15 percent cut, citing high numbers of voluntary departures. Other agencies, such as the IRS and the General Services Administration, have recently brought back workers who took buyouts or were fired.

And the National Weather Service over the summer won permission to hire for more than 100 new positions after cuts left the agency significantly diminished and struggling to keep basic forecasting going, often at the cost of workers’ mental health.