The campaign of a state attorney general candidate hung in the balance yesterday as federal investigators probed whether Jeanine Pirro illegally attempted to eavesdrop on her husband.

Ms. Pirro denounced the investigation of a conversation she had about secretly recording her husband after she suspected he was having an extra-marital affair last summer.

Ms. Pirro termed the probe a partisan attack during the final stretch before Election Day. She admitted that she had her husband, Albert Pirro, followed and discussed the prospect of taping him with a former New York City police commissioner, Bernard Kerik, but said nothing happened that should be investigated by the U.S. attorney’s office.

“I was a very angry woman and I said a lot of things, but what matters is what I did and didn’t do, and I didn’t do anything here other than vent,” she said at a press conference.

The U.S. attorney for the southern district of New York is investigating whether tape-recorded conversations between Ms. Pirro and Mr. Kerik construe a violation of federal law prohibiting wiretaps and electronic eavesdropping.

Title 18 of U.S. Code Section 2511(1) says attempting to get a third party to intercept or endeavor to intercept wire, oral, or electronic communications is a crime that carries a penalty of up to five years in prison.

Ms. Pirro contended yesterday that the investigation led by Assistant District Attorney Elliot Jacobson was “personal and highly improper.” Mr. Jacobson prosecuted her husband in 2000 on charges of wire fraud. He was found guilty and served 11 months in prison.

The chief attorney at the southern district, Michael Garcia, a Republican, dismissed charges that his office was acting with an agenda.

“We do not take politics into account in deciding either the subject matter or timing of investigations,” he said in a statement.

The chairman of the state Republican Party, Stephen Minarik, said he was standing by the party’s choice for attorney general.

“This is a political leak five weeks before an election,” he said. “New Yorkers will see right through this. We stand 100% behind Jeanine and her candidacy. This is an intensely private matter and should remain that way.”

The Republican gubernatorial candidate, John Faso, declined to comment, a spokeswoman for the campaign said. On Tuesday, Mr. Faso called on the state comptroller, Alan Hevesi, to resign after the comptroller acknowledged that he owed the state more than $82,000 for using a state employee as a chauffeur for his wife.

“Right now, everybody in Republican circles is undoubtedly in a state of shock,” a veteran Republican strategist, Robert Ryan, said. “People will wait for the dust to settle, see how the press reports the story over the next few days, and make an evaluation of the situation.”

One prominent Republican was already moving away from Ms. Pirro by the end of yesterday. A source close to Mayor Giuliani said he would not be going forward with a fund-raiser for Ms. Pirro originally scheduled for October 3.

Ms. Pirro vehemently denied the possibility of bowing out of the race.

“There is no way, when I have the opportunity to be the first woman attorney general in the history of this state, that I am going to be pushed out of a race because somebody wants to delve into the personal lives of my husband and myself,” she said.

Her opponent in the attorney general’s race is Andrew Cuomo.

At this point in the race, Republicans would have few options for getting Ms. Pirro off the ballot, an election lawyer and professor at Fordham Law School, Jerry Goldfeder, said.

“Unless she moves out of state or there is a sleight of hand maneuver where they put her up for Supreme Court Justice, which would enable the party to remove her from the attorney general spot, she is stuck on the ballot,” he said.

The controversy also brings Mr. Kerik, who in July admitted this summer to taking $165,000 in illegal gifts as a city official, back into the spotlight.

Mr. Kerik’s lawyer, Joseph Tacopina, said: “Bernie spoke to a friend in distress regarding a domestic conflict. Nothing illegal was discussed and nothing illegal was done.”

A law enforcement source said that part of Mr. Kerik’s plea deal in July included immunity from any charges that could arise from the federal investigation of Ms. Pirro.

Ms. Pirro defended her decision to stay married to her husband over the years. Pirro has had two highly publicized extramarital affairs since he married Ms. Pirro in 1975, and has fathered an illegitimate child.

“My husband is a great father,” she said, her voice heavy with emotion. “I have two beautiful children in school, a teenage son who needs his father with him. These are personal choices that I have made and I shouldn’t have to keep explaining them.”