Senate Minority Leader Mitch McConnellAddison (Mitch) Mitchell McConnellSessions: 'We should be like Canada' in how we take in immigrants NSA spying program overcomes key Senate hurdle Overnight Finance: Lawmakers see shutdown odds rising | Trump calls for looser rules for bank loans | Consumer bureau moves to revise payday lending rule | Trump warns China on trade deficit MORE’s (R-Ky.) campaign launched a new radio ad that calls attacks from his primary challenger Matt Bevin “absurd, wrong and ridiculous.”

The ad seeks to undermine the credibility of Bevin and the Senate Conservatives Fund (SCF), which has endorsed him, by pointing out inconsistencies in their records.

“Matt Bevin and out-of-state special interest groups are attacking Mitch McConnell. Nothing new. But can you believe them?” a narrator opens the ad.

The narrator quotes PolitiFact calling Bevin's attacks “absurd," adding they were “about what you’d expect from Matt Bevin, who claimed on his resume that he went to prestigious MIT, when he didn't even attend.”

Of the SCF, the narrator points to a recent report that the group, which pushes fiscal conservatism, owns an expensive townhouse in D.C.

“Press reports reveal that they solicit money from people under the guise of advocating for conservative principles but then spend it on a $1.4 million luxury townhouse with a wine cellar and hot tub in Washington, D.C.,” the narrator says.

“So the attacks on McConnell? Absurd, wrong and ridiculous,” the narrator closes.

Bevin's spokeswoman, Rachel Semmel, charged it's McConnell's who's lobbing false attacks.

"Mitch McConnell can run from his record of supporting higher taxes and increased spending, but he can't hide behind false mudslinging. The more Kentuckians are realizing this career politician says one thing in the Commonwealth and does something different in Washington, they are flocking to conservative alternative Matt Bevin," she said.

And SCF Executive Director Matt Hoskins suggested the ad was an indication the group's attacks are working.

"Mitch McConnell is clearly in trouble in this primary or he wouldn't be attacking Matt Bevin and declaring war on conservatives. Mitch McConnell isn't upset because SCF rents a townhouse for office space; he's upset because we're spending money on radio and TV ads that expose his record of voting for bailouts, more debt, higher taxes, and Obamacare funding," he said.

McConnell is favored in his primary against Bevin but has seen persistent opposition from conservatives, and just this week faced a lukewarm reception at the annual Conservative Political Action Conference.

If he wins his primary, McConnell is expected to take on Democrat Alison Lundergan Grimes in the general election.

— This piece was updated at 10 a.m. to reflect comment from Bevin and the SCF.