Rubio's Reclaim America political action committee says in the new ad that Ayotte has sought to reduce gun violence in New Hampshire, home of the nation's first presidential primary. The ad points to "safety, security, family. No one understands these things like a mom and no one works harder for them than this one."
Ayotte opposed a key part of President Barack Obama's push to curb gun violence, a measure that would have required expanded background checks for people who buy guns online or at gun shows.
Since the vote, the senator has been criticized in tough ads aired by gun control advocates led by wealthy New York Mayor Michael Bloomberg. She was recently confronted at a town hall meeting by a woman whose mother was killed in last year's school shooting in Newtown, Conn.
Rubio is a potential 2016 presidential candidate who is seeking immigration reform in the Senate. Rubio's PAC estimated the ad buy was in the "six figures."