In guidance posted Monday on the department’s website, the Labor Department said it would be “inappropriate” for companies to send 60-day notices to their employees. That is because of the uncertainty about whether the reductions will occur or which jobs will be cut, the department said.

Legal notice “to employees of federal contractors, including in the defense industry, is not required 60 days in advance of January 2, 2013, and would be inappropriate, given the lack of certainty about how the budget cuts will be implemented and the possibility that the sequester will be avoided before January,” the department said.

The department was clarifying requirements under the Worker Adjustment and Retraining Notification Act, also known as the WARN Act.

Companies led by Lockheed Martin Corp., the world’s largest defense contractor, have said federal and state laws may require them to issue notifications of potential job cuts days before the November 6 election unless President Barack Obama and Congress act to avert automatic defense reductions of $500 billion over a decade that would start on Jan. 2.

Partisan Fight Brewing

The Labor Department guidance, prepared for state agencies that aid laid-off workers under the law, comes as a partisan fight is building over the defense reductions, with Democrats insisting that Republicans agree to some tax increases to avert the cuts. The cuts stem from last year’s clash over raising the debt limit, with the automatic cuts employed as a fallback if both parties couldn’t agree on a broad debt-reduction package

Companies and industry groups, such as the Aerospace Industries Association, are also demanding more clarity from the White House and Pentagon over how the cuts will be implemented. The defense cuts amount to about a 10 percent reduction.

The federal WARN Act, which became law in 1988, requires most employers with 100 or more workers to give 60 days’ notice of plant closings or “mass layoffs” -- labor cutbacks affecting 500 or more workers, or at least 33 percent of the workforce for companies with fewer than 500 employees.

Industry trade groups have predicted the automatic cuts may cost 1 million U.S. jobs, and Robert Stevens, chairman and chief executive officer of Bethesda, Maryland-based Lockheed, has led the way in discussing the possibility of mass WARN Act notices.

Tell Everyone

“It is quite possible that we will need to notify employees in the September and October time frame that they may or may not have a job in January depending upon whether sequestration does or does not take effect,” Stevens said at an investor’s conference in New York on May 31. “Because the level of planning detail really isn’t available, we may have to notify every one of our employees, and all of our suppliers and subcontractors that they may or may not have a subcontract.”

Stevens on July 18 testified before the House Armed Services Committee that his “back of the envelope” estimate is that Lockheed would have to cut 10,000 jobs if the spending reductions go forward.

Other defense firms, including Northrop Grumman Corp. and United Technologies Corp., have not indicated they may send notices widely. Top officials at the aerospace trade group, which represents them and other firms, have raised the possibility that member companies may have to send the notices due to the uncertainty of the so-called sequestration.

‘Not Appropriate’

In its guidance, the Labor Department said it would be “inconsistent” with the purpose of the WARN Act to send the notices as the sequestration looms. The purpose is to help workers who will lose their jobs get training or find other jobs, and the notices are very specific about exactly which jobs and plants are affected.

The preamble of the WARN Act regulations state outright that “it is not appropriate for an employer to provide blanket notice to workers,” the Labor Department said.