Updated

The Pentagon on Sunday called back to work most of its roughly 400,000 civilian employees, based on administration lawyers’ legal interpretation of the recent government slimdown.

The order was given by Defense Secretary Chuck Hagel, five days after roughly 800,000 federal workers were sent home after Congress failed to reach a deal to fund the government.

Hagel said the decision to recall the workers is based on a Pentagon legal interpretation of a law called the Pay Our Military Act.

The measure was passed by Congress and signed by President Obama shortly before the slimdown began.

“Attorneys concluded that the law does allow the Department of Defense to eliminate furloughs for employees whose responsibilities contribute to the morale, well-being, capabilities and readiness of service members,” Hagel said in a written statement. “This has been a very disruptive year for our people … .Many important activities remain curtailed while the shutdown goes on.”

Hagel signaled earlier in the past week that Pentagon lawyers were trying to determine ways for some of the department's furloughed civilians to get back to work.

In a memorandum from Hagel to other high-ranking military officials and obtained by Fox News, the Defense secretary states member of the military reserves and full-time National Guardsman are among those being asked to return.

Hagel told reporters traveling with him Tuesday in South Korea: "It does have an effect on our relationships around the world and it cuts straight to the obvious question, ‘Can you rely on the United States as a reliable partner to fulfill its commitments to its allies?’ "

The Pentagon did not immediately say on Saturday exactly how many workers will return to work. The Defense Department said "most" were being brought back.

Massachusetts Democratic Sen. Ed Markey praised the move and blamed the slimdown-related furloughs on the “Tea Party Republicans.”

"This is the right decision for the hundreds of thousands of patriots who support our soldiers, and now it's time to end this harmful government shutdown that has left hundreds of thousands of other federal workers sitting at home," Markey said.

Washington Republicans did not return requests for comment.

The law ensured that members of the military, who have remained at work throughout the shutdown, would be paid on time. It also left room for the Pentagon to keep on the job those civilians who provide support to the military.

Hagel also said Saturday that he strongly supports efforts in Congress to enact legislation to retroactively compensate all furloughed employees. "And I will continue to urge Congress to fulfill its basic responsibilities to pass a budget and restore full funding for the Department of Defense and the rest of the government," Hagel said.

The Associated Press contributed to this report.