The Congressional campaign of Republican George Demos is out with a new TV ad on Thursday that stars a top-billed endorser: former New York City Rudy Giuliani.

In the ad, which features the one-time presidential candidate talking directly into the camera, Giuliani urges voters to to not “believe the attacks” opponents of Demos.

Giuliani also touts Demos’s resume as a former SEC prosecutor.

“I ran for Mayor to fix the mess in New York City,” Giualini says. “Like me, my friend George Demos was a prosecutor, and he’s running for Congress to fix the mess in Washington. Don’t believe the attacks from his opponents. I know George Demos. He’s a man of integrity and character.”

Demos faces state Sen. Lee Zeldin in the June Congressional primary, part of what’s becoming an increasingly heated campaign.

Demos has been blasted by supporters for Zeldin, who has the support of most of the GOP establishment in the state, including state Republican Chairman Ed Cox.

In addition to Giuliani, Demos was endorsed by former Gov. George Pataki.

Zeldin has vehemently denied claims from the Demos campaign that he approved funding for Obamacare in the state budget, which used federal pass-through funds.

Nevertheless, the Senate’s one-house budget resolution cut spending for the state’s health exchange.

Both are competing to take on Democratic incumbent Rep. Tim Bishop in the Suffolk County congressional district.