A Democratic super PAC is up on the air in Virginia, seeking to counter recent conservative ad buys with a new spot attacking George Allen (R) and praising Timothy M. Kaine (D).

The two former governors are squaring off for the seat of retiring Sen. James Webb (D) in a high-profile and expensive contest that continues to attract significant outside spending. The pro-Republican Crossroads GPS launched an ad last week accusing Kaine of “leaving Virginia behind,”and now Majority PAC has returned fire with a spot reminding viewers of Allen’s previous tenure on Capitol Hill.

“Only one candidate for Senate actually served in Congress, and look what George Allen did to Virginia when he was there,” the ad says, accusing Allen of casting votes to grow the budget deficit and weaken Medicare. The spot then contrasts that record with Kaine’s when he served as Virginia governor.

The Majority PAC spot is running in Richmond, Norfolk, Roanoke and Washington. The group is also airing spots to aid Democratic Senate candidates in Missouri, New Mexico, North Dakota and Ohio.

“It’s disappointing but not surprising that Chairman Kaine’s allies are coming into Virginia on his behalf to attack George Allen, with this latest group supported by Senators Harry Reid, Chuck Schumer and Barbara Boxer,” said Allen spokeswoman Emily Davis, accusing the group of trying to “rewrite” Kaine’s poor record as governor.