A Northeast liberal running attack ads in Arkansas could end up helping Pryor.

Washington (CNN) – A large gun advocacy group is hitting its first Democrat in their most recent campaign to increase gun control measures.

Mayors Against Illegal Guns, founded by independent New York City Mayor Michael Bloomberg, announced an ad Friday criticizing Democratic Sen. Mark Pryor for his recent vote against gun legislation in the Senate, including expanding background checks.

A spokesperson for the organization said they are putting $350,000 into 30-second spot, which features a woman who lost her friend to gun violence.