Jimmy Jenkins/KJZZ

Arpaio campaign attorney Kory Langhofer responds to a defamation lawsuit brought by Paul Penzone against Sheriff Joe Arpaio.

Sheriff Joe Arpaio is facing a lawsuit after airing an attack ad against his opponent in the race for Maricopa County Sheriff.

Paul Penzone is suing Arpaio for defamation for running an ad accusing Penzone of abusing his ex-wife. The allegations stem from an incident in 2003 when Penzone had an altercation with his then estranged wife, Susan Hubbard.

Hubbard has since said in an affidavit that allegations of physical aggression between them are inaccurate. Arpaio ran a similar ad against Penzone in 2012.

At a press conference on Thursday announcing the lawsuit, Penzone defended himself again.

“I never at any time harmed my ex-wife or any woman in my life,” Penzone said.

Kory Langhofer, counsel for the Arpaio campaign called the lawsuit a political stunt and said the ad is based on public records including a police report detailing Hubbard’s initial accusations against Penzone.

"The First Amendment doesn’t protect politicians from criticism," Langhofer said. "It guarantees that citizens will have the right to find out information about politicians and share it with others before citizens go to the ballot box to vote.”

Polling shows Arpaio in a tight race with Penzone as the incumbent Sheriff seeks his 7th term in office.

EDITOR'S NOTE: This story was updated to reflect Arpaio ran a similar ad against Penzone in 2012.