Senate Republican Leader Mitch McConnell got his first big challenge from the right Wednesday, as the conservative group ForAmerica launched an ad questioning whether the Kentucky Republican is a true conservative.

The same group, though, gave McConnell a stellar 95 percent average rating.

McConnell, the leader of the Senate's 45 Republicans, is up for re-election next year. He negotiated a deal with Vice President Joe Biden last week to avoid the fiscal cliff. The package included tax increases on the wealthy and delayed automatic spending cuts two months.

"As negotiations over the so-called fiscal cliff were intensifying," the ad says, "conservatives called on McConnell and congressional Republicans to hold the line on tax rates and demand cuts to spending as they had promised."

instead, ForAmerica says, "when the deadline was looming, McConnell called Vice President Joe Biden and signed off on a deal with the White House that included tax increases and virtually no spending cuts."

David Bozell, executive director of ForAmerica, explained why the group is questioning McConnell after giving him a high rating:

“The Fiscal Cliff vote will soon be integrated into the Freedom Meter but, as everyone knows, it only takes a few bad test scores to screw up a decent grade – and the deal Senator McConnell cut with liberals is certainly a doozy.

"Going forward, we hope that Senator McConnell stops cutting bad deals with liberal Democrats behind closed doors and stands up for fiscal discipline and economic growth; if he does so then we will enthusiastically support him.”

The group is urging people to sign a petition "to let McConnell and congressional Republicans know conservatives are watching and will hold accountable those who go against the principles they claim to support."

No candidate is mentioned. Despite his conservative record, McConnell is well aware that Tea Party conservatives can show strength in Kentucky.

While no major Democrat is likely to challenge him, in 2010 the more conservative Rand Paul beat  McConnell’s handpicked choice for the state’s other Senate seat, Secretary of State Trey Grayson, in the party primary.

In a November interview with McClatchy, McConnell said 2014 wasn’t foremost on his mind. “I don’t want to be overly confident here. I don’t own my seat,” he said. “My only concern right now is not what might happen in 2014 but what might happen in the next three or four weeks.”

Asked whether he’s running, he lets out a big smile. “I’m running. Read my lips, I’m running,” he said. And he’s embraced Paul, even hiring Jesse Benton, who ran the presidential campaign this year of Paul’s father, U.S. Rep. Ron Paul, R-Texas, to run the 2014 re-election effort.