The Trump administration is planning to furlough the vast majority of the civilian staff at a key agency that helps manage the nation’s nuclear weapons stockpile, according to a notice obtained by POLITICO.

The National Nuclear Security Administration, which falls under the Energy Department, will exhaust its available funding on Saturday, according to the notice NNSA sent to lawmakers.

As a result, approximately 1,400 employees will be furloughed, the notice states, while about 375 will remain on the job for work that has been exempted from the shutdown. In all, about 80 percent of the agency’s personnel won’t report to work on Monday.

The agency doesn’t directly operate U.S. nuclear weapons, which falls to the Pentagon. But it is a key component of America’s nuclear capabilities by maintaining and modernizing warheads, overseeing Navy nuclear propulsion and managing nonproliferation programs. Republicans on Friday warned there could be consequences because of the furloughs, though the memo to lawmakers states the Energy Department and NNSA “are looking at all options to ensure continuity of our critical national security missions.”

House Armed Services Chair Mike Rogers (R-Ala.), alongside House GOP leaders, said at a news conference Friday that “another consequence” of Senate Democrats blocking the Republican-backed funding stopgap was staff reductions at the National Nuclear Security Administration.

“We were just informed last night that the National Nuclear Security Administration, the group that manages our nuclear stockpile, that the carryover funding they’ve been using is about to run out,” said Rogers. “They will have to lay off 80 percent of their employees. These are not employees that you want to go home. They’re managing and handling a very important strategic asset for us. They need to be at work and being paid.”

A House Armed Services spokesperson clarified, however, that the panel was told those staff were being temporarily furloughed and not completely laid off.

Rogers and other top Republicans, led by Speaker Mike Johnson, cited the nuclear workforce furloughs as just one of the looming national security consequences of the shutdown and blamed Senate Minority Leader Chuck Schumer for keeping agencies shuttered.

Though the Republicans praised President Donald Trump for shifting Pentagon funding to ensure troops didn’t miss a paycheck this week, Rogers noted defense civilian workers are still going unpaid and other major national security functions will be impacted as the shutdown drags on.

“People are about to start missing paychecks,” said Rogers in an interview after the GOP press conference. “That’s when it gets painful.”

The Energy Department in a statement confirmed that approximately 1,400 NNSA employees will be furloughed as of Monday while “nearly 400″ will continue working. The NNSA’s Office of Secure Transportation — which oversees the safe transportation of U.S. nuclear materials, such as weapons, components, enriched uranium or plutonium — is funded through Oct. 27.

Energy Secretary Chris Wright, a spokesperson said, will travel to the NNSA’s Nevada National Security Site on Monday to highlight the shutdown’s impact on the U.S. nuclear enterprise.

Energy Department officials have been sounding alarms that the shutdown would result in halting some nuclear security programs and staff furloughs.

Wright said in an interview Thursday on Bloomberg TV that furloughs at the NNSA could occur as soon as Friday, saying the agency won’t be able to pay those workers by “Monday at the latest.”

Kelsey Tamborrino contributed to this report.