Timothy M. Kaine upped the ante Thursday in the battle over seniors in Virginia, launching a new ad hitting George Allen for his record on Social Security and Medicare.

As Allen (R) and Kaine (D) duel for the seat of retiring Sen. James Webb (D), both former governors are eyeing older voters as a key constituency. A Washington Post poll released last week showed them basically tied among voters 65 and older, a shift from a May Post poll that gave Allen a big advantage.

In Kaine’s latest spot, the narrator says that when Allen was in the Senate, he “voted to partially privatize Social Security. And he voted to cut Medicare.” (The first vote was on a 2006 measure creating a Social Security reserve fund to pay for optional private accounts; the second was on a 2005 budget “reconciliation” bill that reduced spending across government, including Medicare.)

“Allen now favors a plan that would increase costs for seniors and the middle class by thousands of dollars a year,” the narrator says, a reference to Allen’s support for repealing President Obama’s health-care law.

Allen spokeswoman Emily Davis called Kaine’s spot “another negative, misleading attack ad.”

“While George Allen has a proven record of working with others to strengthen Social Security and expand Medicare coverage, Tim Kaine thinks he can back seniors into his corner with enough frightening claims about their benefits,” Davis said, while noting that Kaine supported the Affordable Care Act, which would be partly funded by reducing future spending on Medicare.

Kaine’s ad comes the same week the Democratic Senatorial Campaign Committee released its own commercial attacking Allen on Social Security.