In a preview of what may be coming in 2014, the Senate Conservatives Fund has booked a $340,000 television ad attacking a Republican leader over Affordable Care Act funding.

The ad lambasts Senate Minority Leader Mitch McConnell (R-KY) for refusing to join a GOP proposal to vote against any appropriations bill that contains Obamacare funding. It is expected to run through Sept. 17.

“McConnell’s the Senate Republican leader, but he refuses to lead on defunding Obamacare,” the ad says, according to the National Journal. “What good is a leader like that?”

Cutting off funding could lead to a government shutdown, which some Republican leaders believe would backfire. 

McConnell is facing a primary challenge from Kentucky businessman Matt Bevin.