Defense Secretary Leon E. Panetta has notified Congress that the Defense Department is prepared to implement furloughs for civilian personnel in response to the threat of sequestration.

In a memo to all employees, Panetta vowed to continue working with Congress to avoid sequestration, which would add $470 billion to the $487 billion in defense spending cuts the department already is making over the next 10 years. If Congress cannot agree on an alternative deficit reduction plan, the cuts go into effect March 1.

Panetta and every other defense leader have called the cuts dangerous. They would come on top of cuts imposed by operating under a continuing resolution. For fiscal year 2013, the effect will be further magnified, because the cuts must be done in the final six months of the fiscal year, which ends Sept. 30.

“In the event of sequestration, we will do everything we can to be able to continue to perform our core mission of providing for the security of the United States,” Panetta wrote in the memo, “but there is no mistaking that the rigid nature of the cuts forced upon this department, and their scale, will result in a serious erosion of readiness across the force.”

Panetta and DOD leaders long have expressed deep concern about the direct impact sequestration will have on military personnel, civilian employees and families. Flexibility in sequestration is limited, the secretary said in his memo, noting that while military personnel are exempt from direct impact, services on bases will deteriorate, and families may feel the pinch in other ways.

Civilian employees will be furloughed if sequestration is triggered. Deputy Defense Secretary Ashton B. Carter said last week that civilian employees could lose 20 percent of their normal income through September.

“I can assure you that, if we have to implement furloughs, all affected employees will be provided at least 30 days’ notice prior to executing a furlough, and your benefits will be protected to the maximum extent possible,” Panetta wrote.

DOD will work to ensure furloughs are executed in a consistent and appropriate manner, the secretary said, and Pentagon officials also will continue work with employee unions.

“Our most important asset at the department is our world-class personnel,” Panetta wrote. “You are fighting every day to keep our country strong and secure, and rest assured that the leaders of this department will continue to fight with you and for you.”