Senate Minority Leader Mitch McConnell (R-Ky.) chuckled at the end of a radio interview recently when a host told him he hoped the lawmaker would vote "no" on extending federal unemployment benefits. Now, McConnell's Democratic challenger, Kentucky Secretary of State Alison Lundergan Grimes, has gone on the attack.

In a Jan. 8 interview with conservative talk radio host Lars Larson, McConnell said Republicans would extend federal benefits for the long-term unemployed if the Affordable Care Act's individual mandate is delayed for one year.

"I hope you vote no on extending unemployment benefits," said Larson at the end of the interview, to which McConnell laughed in response.

Larson followed-up, "at least for the long-term unemployed, I appreciate it."

"Yeah, thanks Lars," McConnell said.

Listen to a clip of the interview below. The exchange is in the last 30 seconds:

The Grimes campaign slammed McConnell in response to the interview:

It is shameful that after failing for nearly 30 years to offer a credible plan to put Kentucky back to work, Mitch McConnell has the audacity to laugh in the faces of more than 18,000 unemployed Kentuckians, including 1,200 coal miners in Pike County," Grimes spokeswoman Charly Norton said. "The people of Kentucky deserve a senator they can be proud of -- not one who offensively looks down upon our people and is an embarrassment to the values we hold dear. We take care of our own in this state. As senator, Alison Lundergan Grimes will never turn her back on the hardworking men and women of the Commonwealth.

The campaign also unveiled a graphic featuring a picture of McConnell over a shot of the Capitol that says, “Mitch McConnell’s answer on how he will vote on extending unemployment benefits? 'Ha ha ha ha.'"

Long-term unemployment benefits expired on Dec. 28 for 1.3 million Americans. President Barack Obama and congressional Democrats want an extension of the program, which kicks in when state benefits expire.

Proposals to reauthorize the benefits failed in the Senate on Tuesday. And even if the Senate approved legislation to extend the benefits, the Republican-controlled House of Representatives would still have to also vote on the bill before it could go to Obama to be signed into law.

In an editorial for Politico, McConnell wrote that the debate over extending unemployment insurance is representative of broader problems with the Senate:

In this debate, Senate Democrats seem far more interested in providing temporary relief from the pains inflicted by the Obama economy than in working on ways to help people escape it. But Sen. Reid’s refusal to even debate common-sense reforms that would help those struggling with long-term joblessness, or sensible proposals to cover the cost of assisting them, only makes sense in the larger context of his tightening hold on the legislative process.

McConnell's campaign spokeswoman Allison Moore told The Huffington Post that Grimes' campaign was "resorting to desperate misrepresentations." Moore also said the graphic was "false advertising."

Matt Bevin, a tea party-backed businessman, is challenging McConnell in an increasingly contentious Republican primary.

HuffPost Pollster, which combines all publicly available polling data, shows McConnell leading Grimes, 42 percent to 38 percent.