HARRISBURG — Pennsylvania's gubernatorial candidates sparred Tuesday over which of them would be more likely to increase state taxes.

At a news conference, Democrat Dan Onorato labeled Republican opponent Tom Corbett "the only candidate who has raised property taxes." For proof, he reached back more than two decades to Corbett's 1988 vote to increase local property taxes during his brief stint as a Shaler Township commissioner in Western Pennsylvania.

A campaign spokesman for Corbett, the state attorney general, dismissed Onorato's news conference as "a desperate act by a desperate candidate."

Onorato, who is Allegheny County's elected chief executive, said he has never supported higher property taxes.

"As county executive, I enacted six balanced budgets without raising property taxes," Onorato said at the news conference in Shaler Township. "Tom Corbett enacted one budget with a 20 percent property-tax increase."

Corbett campaign spokesman Kevin Harley promptly pointed out that Onorato supported a stiff tax on alcoholic drinks served in bars to raise millions for mass transit. The campaign also distributed a list of newspaper clippings about other tax increases that Onorato supported during his eight years on the Pittsburgh City Council. The property tax was not among them.

"Dan Onorato has never met a tax he didn't like or didn't hike," Harley said.

Corbett, who has spent most of his career as a state or federal prosecutor, has signed a pledge to oppose new taxes if he is elected governor. However, he told The Associated Press in a July interview that the pledge would not stand in the way of increases in fees — for such items as vehicle registrations and driver's licenses — and other levies that are not called taxes.

As a county executive, Onorato said he has fought against property-tax reassessments that would have forced homeowners to pay more in taxes, while shrinking the county payroll and streamlining the county government.

"We have to make the state live within its means and I am the only candidate who can get the job done," he said.

Harley said Onorato should put his intentions in writing, as Corbett as done.

"If Dan Onorato is serious about limiting taxes, then he should join Tom Corbett in signing a no-new-tax pledge," he said.