WASHINGTON – Rep. Vito Fossella of New York acknowledged on Thursday that he fathered a child from an extramarital affair, answering questions that arose from his arrest on drunken driving charges last week.

“My personal failings and imperfections have caused enormous pain to the people I love and I am truly sorry,” said Fossella, a Republican, who has three children with his wife in Staten Island, N.Y.

Fossella is the only Republican member of Congress from New York City, and the paternity revelation could lead to the loss of a seat in Congress at a time when the House GOP faces the possibility of a second grim November of election setbacks.

Fossella’s private life came under scrutiny after he was arrested last week in the Virginia suburbs of Washington.

When Fossella was pulled over, police said he told officers that he was going to see his daughter in the area. That prompted questions about who the daughter was.

“I have had a relationship with Laura Fay, with whom I have a 3-year-old daughter,” Fossella said in his statement. It was Fay who got him out of jail after the arrest. She is a former Air Force lieutenant colonel and worked for a time as a liaison to Congress.

Police said Fossella’s blood-alcohol level was twice the legal limit, and he could face a mandatory five days in jail if convicted. A court appearance on the drunken driving arrest that had been planned for next week was canceled, and he is now not expected back in court until June.

Fossella said he had no immediate plans to resign. The disclosures are a crushing blow to the career of a lawmaker once seen as a potential candidate for mayor of New York City. He faced a surprisingly tough re-election challenge in 2006, and Democrats have been hoping to unseat him this year.

“While I understand that there will be many questions, including those about my political future, making any political decisions right now are furthest from my mind. Over the coming weeks and months, I will continue to do my job and I will work hard to heal the deep wounds I have caused,” he said.

If he was looking for public support to remain in office, there was little in the wake of his announcement.

A spokeswoman for the House GOP campaign committee said only that it expects the district to continue to elect conservative-minded lawmakers. A spokeswoman for the Democratic campaign committee declined to comment.

Fossella, 43, was elected to Congress in 1997 in a special election to replace Rep. Susan Molinari, who resigned. His socially conservative positions squared nicely with his largely Catholic district. He serves as a member of the House Committee on Energy and Commerce.

Fossella’s work in Congress shifted dramatically following the Sept. 11, 2001, terror attacks.

Hundreds of Staten Island residents died in the attacks, and Fossella became a prominent advocate for families of those killed.

As more recovery and rescue workers got sick after toiling at the ground zero site, Fossella pushed for Washington to pay for their health care — an effort that has met with short-term success but no long-term program.