Topeka ? Democrats’ complaints prompted Republican Sen. Pat Roberts to modify his latest television ad, but he hasn’t dropped a theme that could be helping his re-election campaign in the short-term.

Roberts’ campaign made what spokeswoman Molly Haase described as “two small tweaks” over questions of whether the 30-second spot complied with a federal “Stand by Your Ad” requirement.

The questions were raised by Mike Gaughan, the Kansas Democratic Party’s executive director, in a complaint to the Federal Election Commission. He doesn’t plan to withdraw his complaint.

Democrats continued Thursday to criticize the GOP incumbent because the ad attacks former Rep. Jim Slattery, the Democrats’ leading Senate candidate. And a Slattery aide acknowledged that Roberts’ advertising may have widened the gap between the two candidates in recent weeks.

“Anytime you spend hundreds of thousands of dollars running negative ads against your opponent, they will likely have some effect,” said Slattery spokeswoman Abbie Hodgson.

Roberts has made Slattery’s work as a Washington lobbyist an issue. The ad began airing last week in Topeka and Wichita. It praises Roberts and describes Slattery as “helping the special interests that made him rich.”

Slattery represented the 2nd District of eastern Kansas in 1983-94, ran unsuccessfully for governor in 1994, then became a lobbyist. Slattery disclosed earning $585,000 working for a major Washington law and lobbying firm in 2007.

“We are telling the truth. Kansans deserve to hear the truth,” Haase said. “No amount of whining will change that.”

Slattery faces Lee Jones, an Overland Park railroad engineer and former union leader, in the Aug. 5 primary. But most Democrats expect Slattery to win the nomination easily.

Slattery has yet to start TV ads, though Hodgson said it would begin “in the near future.”

In his FEC complaint, Gaughan said audio and written statements in which Roberts and his campaign took responsibility for it weren’t worded and placed properly. Gaughan also said one image of Roberts wasn’t clear enough.

Roberts’ campaign revised the disclaimers and chose a new image of the senator but didn’t change the message.