"My daughter didn't want me to run because the guy lies," Melancon (D) told The Ballot Box on Thursday. "The amazing part is he's accusing people of lying about him."

Melancon was on the receiving end of a hard-hitting TV ad released by Vitter (R-La.) earlier this month. The spot accused the Democrat of supporting government benefits for "illegals" and using $50,000 to "get himself a luxury SUV."

"That's how David VitterDavid VitterMercury brings on former Sen. Vitter, two others Lobbying World Bottom Line MORE runs his campaigns, but I'm not going to let him run over me," Melancon said. "The gloves have been off but we knew it was [coming]."

Vitter's campaign said the Republican has been focused on "the issues."

"From day one, Senator Vitter has made his re-election campaign about the issues important to Louisiana families," Luke Bolar, a spokesman for Vitter, said in a statement. "From day one, Charlie Melancon has tried to distract from his terrible voting record supporting Obama's massive spending, the bailouts, and taxpayer funded benefits for illegals."

Meanwhile, Melancon has released a harsh TV ad of his own, targeting the Vitter's record on women's issues and his admission to a "serious sin."

Vitter was identified as a client of a prostitution ring in 2007. Despite the scandal, he is favored to defeat Melancon.

A Republican source said the ad's release in August, as opposed to October, was a sign of desperation on the part of the Democrat. Melancon is trailing Vitter by double digits in most public polls, and observers believe he needs to show party strategists some movement or they'll direct resources elsewhere in the fall.

Melancon denied the "serious sin" ad was meant for October.

"My first ad was to come out positive," he said. "But we had a bad one in the can, because we figured if we came out positive he'd come out attacking, which he did, so we threw one out about the serious sin.

"That's the beginning," he said. "This race actually starts on Sunday because we're going to get through the primary."

Louisiana's primary vote is on Saturday. Melancon and Vitter are both expected to emerge as the nominees for their respective parties.

Melancon hinted he would continue to target Vitter's record.

"When they start seeing what his record is, it's starting to turn this election around," he said. "We're feeling good about the response we're getting statewide."

—Updated at 7:38 p.m.