On Monday, the National Nuclear Security Administration (NNSA) placed over 75% of its workforce on furlough as the government shutdown approaches the end of its fourth week.

A representative from the Department of Energy shared with The Hill that by the conclusion of Monday, 1,400 employees at the NNSA would be furloughed, leaving fewer than 400 individuals to manage the agency’s critical task of overseeing the country’s nuclear arsenal.

“As a result of the Democrat-led shutdown, around 1,400 NNSA federal staff will be furloughed starting today, October 20th, while nearly 400 will remain on duty to ensure property protection and human safety,” stated the spokesperson.

They further mentioned that funding for the NNSA’s Office of Secure Transportation has been secured for one more week, until October 27th.

Ben Dietderich, another spokesperson for the Energy Department, informed CNN that this marks the first instance in the NNSA’s 25-year history where employees have been furloughed due to a government shutdown.

“We are left with no choice this time. We’ve extended funding as long as we could,” Dietderich said.

“While the Energy Department and NNSA remain committed to ensuring the safety and security of America’s nuclear deterrent, the longer the shutdown lasts, the more damaging and dire the consequences will be for workforce retention and weapons modernization efforts critical to national security,” Dietderich added in the statement to CNN.

The government is on Day 20 of a shutdown, as no real negotiations appear ongoing between the two sides. Democrats continue to insist that the enhanced Affordable Care Act (ACA) subsidies, which are set to expire at the end of the year, be expanded before they lend their support to a GOP proposal to reopen the government.

Filip Timotija contributed reporting.