By Alexandra Jaffe - 05/08/13 06:42 PM EDT
In the ad, a narrator asks if viewers have "seen this TV ad paid for by New York City Mayor Michael Bloomberg," a reference to an ad run by Bloomberg-backed Mayors Against Illegal Guns hammering her for the vote.
"Don't believe it," the narrator says.
The ad goes on to highlight a series of Ayotte's votes that it characterizes as working to improve background checks, reform the mental health system and increase resources to prosecute criminals using guns.
It's backed by a $25,000 buy and will run on Manchester-area WMUR for at least a week.
According to a Public Policy Polling survey, half of voters said Ayotte's vote on background checks made them less inclined to vote for her, and only a quarter said it made them more likely to support her.
That same poll showed an 11-percentage-point surge in New Hampshire voters who view her unfavorably since October.
Ayotte isn't up for reelection until 2016, but that polling has given gun control advocates reason to look at her as a possible vote in favor of gun control if they get another try at the measure that failed in the Senate last month.