Sen. Dick Lugar's (R-Ind.) office is firing back against a mail piece from a super-PAC backing Indiana state Treasurer Richard Mourdock's (R) Senate campaign.

The group, which also worked to help Mourdock beat Lugar in the primary, sent a mail piece stating, "Indiana's Lugar Backs Mourdock in Senate Run."


Lugar's office disagreed.

"During the primary, Mourdock and his supporters perpetuated misleading statements about Sen. Lugar," Lugar spokesman Andy Fisher told Howey Politics Indiana. "Unfortunately, that has continued with this mailer funded by a committee that spent over $100,000 to defeat Sen. Lugar. It was clearly unauthorized and done without consultation with us. Lugar clearly stated on Sept. 17 that he would not campaign for Mourdock in the general election for senator from Indiana." 

Mourdock is engaged in a tight race against Rep. Joe DonnellyJoseph (Joe) Simon DonnellyBiden to have audience with pope, attend G20 summit Biden taps former Indiana Sen. Donnelly as ambassador to Vatican Republicans may regret restricting reproductive rights MORE (D-Ind.). Polls show them neck and neck, with many of the undecided voters being those who backed Lugar in the primary. A September Howey Politics Indiana poll showed only 60 percent of Lugar primary voters committed to backing Mourdock in the general election, and criticism like this from Lugar's side won't help Mourdock's chances at making inroads with that key voting bloc.

Jim Bopp, the head of the USA super-PAC and a longtime conservative activist, responded in an email citing examples of Lugar saying he'd back the man who beat him in the primary.

"I know that there are hard feeling that may not have healed from the primary, but it is incumbent on Republicans to make sure that Congressman Donnelly is not allowed to cynically exploit the situation. He was prepared to run against Sen. Lugar and to defeat him in the general election, except for the results of the primary," Bopp said in a statement after citing articles that indicated Lugar has indeed backed Mourdock.

Lugar said the night of his primary defeat that he hoped Mourdock would win the general election so that Republicans could take over the Senate, but also called for the Tea Party candidate to learn to embrace compromise. He's since said he would not campaign for Mourdock, though he did introduce him to other senators at a closed-door lunch earlier this year.