The ad comes in response to one launched last week by Carmona's campaign that featured clips of the two senators praising Carmona during his 2002 confirmation hearings for U.S. surgeon general. During that hearing, McCain lauded Carmona as "extraordinarily, perhaps uniquely qualified to address the needs of our nation."

Since launching the ad, however, Carmona has faced a backlash from both senators, who charge that it was dishonest of him to use their comments to imply support and that what they said in 2002 should have no bearing on the race today. They have both endorsed Flake for Senate.

Flake's new ad, "Integrity," features the two senators standing side by side speaking directly into the camera about Carmona's ad, with McCain calling it "the most shameful of all."

"We helped Carmona 10 years ago, but found he’s not the kind of man to represent you in the U.S. Senate," Kyl says.

"It isn’t just that he supports the Obama agenda; his ads prove Carmona lacks integrity," McCain adds.

They both repeat that they support Flake.

Many of the attacks on Carmona have surrounded his personality, with Republicans charging that he has a poor temperament when working with women and that he lacks integrity.

It's an effort that will likely continue through the final days of the campaign, as this race remains one of the closest in the nation. The Hill rates the race as a toss-up.