U.S. Sen. Mitch McConnell went on the attack Friday with a TV ad slamming his Democratic challenger on gas taxes — a combustible issue for voters fuming over record-high prices.

The ad links Democrat Bruce Lunsford to a state law that has automatically raised Kentucky’s gas tax, and even shows Lunsford claiming that the taxing formula gave Kentucky “a budget that could grow.”

The 30-second commercial airing across Kentucky says the automatic fuel tax increases have cost residents hundreds of millions of dollars through the years.

Lunsford campaign spokeswoman Allison Haley called the ad a “smoke screen” to divert attention from McConnell’s support for policies that “put us in this mess.” She called McConnell an ally of big oil companies and said gas prices have risen $2.50 per gallon since the senator started his fourth term nearly six years ago.

“On gas prices, McConnell isn’t just part of the problem, he’s helped create the problem,” Haley said.

McConnell, the Senate’s top-ranking Republican, lived up to his reputation as a hard-hitting political tactician by delving nearly 30 years into Lunsford’s past to link him with the formula triggering the gas tax increases.