With news reports saying that defense companies will begin issuing layoffs related to potential military budget cuts before the November presidential election, Republican senators interested in defense are building a legislative case for preventing them.

If Congress fails to reach a deal to reduce the deficit by $1.2 trillion, then in January 2013 cuts of the same amount will be applied to the entire federal budget — with about half targeted at the Pentagon.

Defense executives including outgoing Lockheed Martin CEO Robert Stevens have been warning for months that they will be required to notify employees of potential layoffs well in advance of the January trigger. But given that this is a presidential campaign year, lawmakers are not prepared to address the issue before November.

Sen. John McCain (Ariz.) and other Republicans on the Senate Armed Services Committee have been clamoring all year for Congress to delay the penalty to defense for at least a year. Additional news about potential industry layoffs is prompting them to pick up the pace.

And their latest move is to try to amend the Farm Bill to include a provision that would require the Pentagon to provide a report to Congress about the impact of the penalty known as sequestration. If the amendment, and the bill, pass, it would require the defense secretary to submit the report by Aug. 12.

“Congress needs an official, detailed assessment from the department on the serious damage to military readiness and the increased risk to our military operations in Afghanistan which would result if sequestration is allowed to occur due to the inability of the [Obama] administration and Congress to enact an alternative deficit reduction plan,” McCain says. “The hundreds of thousands of American workers whose jobs are at risk today deserve our immediate attention to the task of averting this potential national security and economic disaster.”

McCain is also asking about the administration’s recent decision to allow war spending accounts to be subject to the penalty. That could cut up to $8 billion from war spending, he says, and “may impact our ongoing military commitments and our ability to keep our troops safe.”