"Michael Bloomberg is New York's ultra-liberal mayor. He's worth $27 billion. His company is embroiled in scandal. Bloomberg tells New Yorkers how much they can drink, and now spends millions telling New Hampshire what to think," a narrator says.
It notes an ad from the Bloomberg group featuring a Minnesota police chief who also served as the former chairman of the International Association of Chiefs of Police Firearms Committee in an ad attacking Ayotte, and pushes back with a New Hampshire police officer touting Ayotte's support for expanded background checks.
"Don't let a New York billionaire use a Minnesota cop to tell New Hampshire what to think," the narrator says.
American Future Fund has spent more than $1.3 million overall in New Hampshire in an effort to defend her against a barrage of attacks on her vote that have come after polling showed the vote hurt Ayotte's support in her home state.
She's not up for reelection until 2016, but gun control advocates see her as one of the likeliest senators to switch their vote if they succeed in bringing the bill back up in Congress.
But a number of conservative groups have come out with ads of their own to counter the attacks, including one from the National Rifle Association and another from Sen. Marco Rubio's (R-Fla.) PAC, touting her support for measures to curb gun violence.
Watch the American Future Fund ad: