Lee Zeldin and George Demos, who face each other June 24 in the Republican primary in Suffolk County's 1st Congressional District, squared off Friday in their first debate, with each candidate professing to be the true conservative in the race.

In an hourlong debate on Long Island News Radio, Zeldin and Demos clashed repeatedly over taxes, education, health care and gun rights. They are vying to unseat Rep. Tim Bishop (D-Southampton) in November.

Demos, 37, a former Securities and Exchange Commission attorney from Stony Brook, accused Zeldin, 34, a two-term state senator from Shirley, of voting for state funding that supported the Affordable Care Act and raising taxes on high income earners.

Zeldin denied the assertions and attacked Demos for not owning a permanent home on Long Island and for funding his campaign through money from his father-in-law, a West Coast developer who has raised money for top national Democrats including House Minority Leader Nancy Pelosi.

"You can't trust this guy," Zeldin said of Demos. "He will do anything to buy his seat in Congress."

Demos called Zeldin a member of the "Albany establishment" and said, "I am the only candidate to stand up for conservative principles."

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Bishop campaign spokesman Keith Davies said in a statement: "Tonight's debate sounded like an audition on 'tea party Idol' with George Demos and Lee Zeldin working to outdo one another and appeal to the tea party conservatives who recklessly caused the government shutdown." The 16-day shutdown in October occurred when House Republicans and Senate Democrats could not agree on a spending bill.

Plying a central theme of his campaign, Demos accused Zeldin of voting for a state budget that includes funding for the Affordable Care Act. Zeldin said the budget only includes federal funds that Gov. Andrew M. Cuomo accepted by executive order.

"I have never supported Obamacare and I never will," Zeldin said.

Zeldin defended his vote in 2011 for a bill that raised income taxes on New Yorkers making more than $2 million per year as a trade-off because the legislation also rolled back a $250 million MTA payroll tax on businesses.

"My opponent has a terrible record in Albany," Demos said. "He voted for higher taxes and Obamacare."

Both candidates said they oppose increasing the federal minimum wage and creating a pathway toward citizenship for undocumented immigrants. Both expressed support for construction of the Keystone pipeline to bring oil to the United States from shale fields in Canada. And they backed repeal of the state's Common Core curriculum testing and the Safe Act, New York's ban on assault weapons.

Zeldin has the backing of the Republican and Conservative parties. Demos touted his support from former New York City Mayor Rudy Giuliani and former Republican Gov. George Pataki.