By Barbara Starr

The Pentagon has begun laying off 46,000 contract and temporary civilian employees in an effort to cut back on military spending, the No. 2 Pentagon official said on Friday.

Full time civilian employees, which number in the hundreds of thousands, also will be furloughed for one day a week for 22 weeks, Deputy Defense Secretary Ash Carter said in an interview with wire service reporters.

His comments were confirmed by a Pentagon spokesman.

The moves are part of a Defense Department effort to reduce spending given the potential for billions in mandatory cuts beginning as early as this spring should Congress fail to reach a deal on deficit reduction.

Defense Secretary Leon Panetta ordered military services to begin implementing cost cutting measures to mitigate the risk of the cuts to the military budget should no congressional deal emerge.

Panetta said earlier this month that he had asked services to begin "prudent" measures, which included curtailing maintenance for non-critical activities and delaying hiring.

The measures must be "reversible" and minimize harmful effects on military readiness, Panetta said.