Pennstlvania- Pennsylvania Republican Don Sherwood, who lost his House seat last fall, is now refusing to pay his ex-mistress more than half of a $500,000 settlement he promised her to keep quiet about their affair, according to two people familiar with the situation.

Sherwood contends he’s no longer bound by the settlement because, he charges, the ex-mistress violated its confidentiality clause, said the sources, speaking on the condition of anonymity because they were concerned about breaching the confidentiality agreement themselves.

The settlement ended a $5.5 million federal lawsuit in which the ex-mistress accused the married father of three of attacking her violently and repeatedly during a five-year relationship.

The ex-mistress isn’t inclined to let Sherwood quietly fade into retirement, one of the sources said. Unless he pays up, she’s likely to bring further legal action against her former beau, who had cast himself as a family-values conservative during four terms representing a heavily Republican district in Northeastern Pennsylvania.

Now 30, the ex-mistress filed the lawsuit in 2005 as Cynthia Mirella Ore, but she changed her name last year, citing “safety from ex-boyfriend” on her name-change petition. It doesn’t name the ex-boyfriend, and she could not be reached for comment. Her attorney, Ronald Karp, said he recently began representing her, but he declined to comment further.

Sherwood, a 65-year-old auto dealer whose financial disclosure statements pegged his net worth at the end of 2005 at a minimum of $3.7 million, did not return several telephone messages left at his dealership. A woman answering the phones said Sherwood and his wife of more than 30 years were vacationing out of state.

Sherwood’s attorney, Sal Cognetti Jr., refused to comment.

The affair came to light in May 2005, when the Wilkes-Barre Times Leader revealed a months-old police report in which an officer wrote that Ore said Sherwood “was giving her a backrub, when (he) began to choke her for no apparent reason.” Sherwood denied abusing Ore, and no charges were filed. But he later admitted the affair and apologized for it.

He and a previous attorney fought to suppress details of the affair while Sherwood campaigned for re-election.

When the suit was settled in November 2005, Republicans predicted Sherwood would be able to put the matter behind him. But political novice Christopher P. Carney, a Democrat written off early by pundits, opened a lead over Sherwood partly by hammering away at the affair. Several days before the midterm vote, the Associated Press reported that more than half of the settlement was to be paid after the election, but only if the ex-mistress kept quiet.

Lawyer Ning Ye, who helped negotiate the settlement for Ore, said he stopped representing her last month and would not discuss specifics of the settlement. But he pointed out that after the agreement, Sherwood appeared in a campaign television ad denying the abuse and asking voters to forgive him for the affair.

“Public admission of the affair is a kind of disclosure,” Ye said. The commercial, he added, revealed elements of “the factual basis leading to the confidential settlement agreement” and, as such, could constitute a violation.