George Allen would like to interrupt his regularly scheduled positive ad blitz for something a bit more ominous.

On the heels of last Saturday's U.S. Senate debate in Virginia, Allen, the Republican candidate, swapped out a light-hearted campaign commercial Tuesday for one attacking a congressional deal to raise the nation's borrowing limit that could lead to sweeping budget cuts, including $500 billion from the Pentagon over the next decade. Allen has blasted Democratic rival Tim Kaine for saying raising the borrowing limit was "the right thing to do."

That debt limit plan was supported, too, by congressional Republicans, including House Majority Leader Eric Cantor, R-Va., and Virginia Gov. Bob McDonnell. Kaine has since called on Congress to find a new deal to reduce the deficit.

But Allen promises to make the looming military cuts an issue moving forward, despite arguments by Kaine and fellow Democrats that the attacks as flatly false. The ad, titled "Devastating," cites a recent George Mason University study that noted Virginia could lose more than 200,000 jobs if the cuts go through.

"Only one candidate for Senate will fight for Virginia jobs and American security," the ad says.

Allen is expected to receive an endorsement Wednesday from the U.S. Chamber of Commerce, an organization that has already run ads attacking Kaine.

But Allen wasn't in the clear Tuesday. Majority PAC, an outfit of Senate Democrats, released an ad claiming Allen was a big-spending Republican when he was in the Senate between 2001 and 2007.

"Allen voted for $121 billion in earmarks," the ad, called "Big Spender," alleges. "Earmarks for imported fire ants; Alaskan berry research; and DNA study of bears in Montana."

Kaine's campaign echoed the ad in a statement denouncing Allen's commercial.

"Let's be clear how we got here," Kaine spokeswoman Brandi Hoffine said. "As a U.S. senator, George Allen took a record budget surplus and turned it into a massive deficit, voted for trillions in new spending, and voted four times to raise the debt ceiling without cutting a dime in spending."

In a statement, Allen's campaign shot back that "Virginians know that Tim Kaine chose to spend his last year as governor traveling the country, giving speeches and raising money to champion Democrats' failed policies that have added $5 trillion to the national debt."

Kaine and Allen, both former governors, are vying for the seat soon to be vacated by retiring Sen. Jim Webb, D-Va.