Correction Appended

The National Republican Senatorial Committee is up with a new Web ad excoriating “Washington lobbyist” Jim Slattery (D) for voting to increase the gas tax when he served in Congress more than 12 years ago.

The spot is a response to a Slattery ad blaming Roberts for rising gas prices.

“For years it’s been clear our energy policies were wrong. But what did Roberts do? Pat Roberts took hundreds of thousands from the big oil companies for his campaign,” Slattery says in his television ad, which features the former Congressman in front of the camera while filling a car up with gas.

“Now we’re all paying at the pump for Washington’s indifference and incompetence.”

The NRSC hits back with an ad that criticizes Slattery for working for a D.C. law firm that included “big oil” as a client.

“In Congress, Slattery voted for [former President] Bill Clinton’s 30 percent increase in the gas tax,” the voiceover in the NRSC ad says. “Pat Roberts voted against the gas tax. And, Pat supports drilling in America to lower our gas prices.”

In a statement released on Monday, Slattery defended his vote.

“There are times as a member of Congress, that I had to make difficult votes. This vote represented my genuine commitment to reducing the deficit,” Slattery said in the statement.

Correction: July 29, 2008

A Web ad produced by the National Republican Senatorial Committee was incorrectly identified as a campaign ad for Sen. Pat Roberts (R-Kan.).