For the first time, lawyer Jose Quinon on Friday publicly confessed he had an affair with the wife of his client, ex-City Commissioner Humberto Hernandez, during his vote-fraud trial.

“There was a relationship,” said attorney Jay Hogan, representing Quinon at a court hearing. “It lasted from the night of jury selection until the trial was over.”

Citing the sex scandal between Monica Lewinsky and President Clinton, Hogan said: “I don’t want an Esther-gate.” He was referring to Esther Hernandez, 34, the wife of the convicted ex-Little Havana politician.

Humberto Hernandez, 36, is pressing to overturn his misdemeanor vote-fraud conviction in August, arguing that his wife’s liaison with his attorney constituted a conflict of interest.

Miami-Dade Circuit Judge Roberto Pineiro set a Jan. 28 hearing to consider Hernandez’s request for a new trial on charges he helped cover up tainted absentee ballots in the 1997 Miami election.

Esther Hernandez, a school teacher and mother of their two children, could not be reached for comment. But she told a reporter for The Miami Herald that she had an affair with her husband’s prominent attorney during his high-profile trial.

Humberto Hernandez cited the newspaper article as justification for a new trial. But Assistant State Attorney Joe Centorino wants Pineiro to consider possible sworn statements from Esther Hernandez and Quinon before deciding on a new trial.

“We would be foolish to stipulate to something that would be in The Miami Herald,” Centorino said.

Quinon’s relationship with Esther Hernandez — they were seen kissing during a Friday night happy hour at Senor Frog’s in September, a few weeks after Hernandez was convicted on vote-fraud charges — provoked the Miami branch of the state Bar to launch an ethics inquiry that might lead to his disbarment.

In October, a federal judge ordered Quinon, 48, to avoid all contact with Humberto Hernandez and to turn over all of his fees earned from representing him in his state vote-fraud trial and in his federal mortgage-fraud defense.

Quinon, who lives with his wife, Louise, and their three children in Coconut Grove, deposited about $235,000 in legal fees with the court.

That money is to be used by Hernandez’s new attorney, Milton Hirsch, as he presses for a second trial. At the first trial, Pineiro sentenced Hernandez to one year in jail.

Today, Humberto Hernandez remains at the Federal Detention Center in Miami. And Quinon’s once-brilliant career, built after 23 years of defending drug kingpins and crooked politicians, is in jeopardy.

Quinon has remained silent since his relationship with Esther Hernandez became public in October. But those who know him say they are baffled by a misstep that seems so out of character for the meticulous workaholic.

“I remain flabbergasted at the conduct, which has been admitted in court by another respected lawyer, Jay Hogan,” said Ben Kuehne, president of the Miami-Dade County Bar Association. “It’s troubling, because Jose has always been a tremendous lawyer and a fine model for the best of the law profession. This is professionally a stumble.”

Born in Cuba, Quinon moved with his family to the United States in the summer of 1962. The family was processed through the Freedom Tower in Miami, and soon after moved to Paterson, N.J. Quinon earned his bachelor’s degree at Seton Hall University in South Orange and his law degree from Rutgers University at Newark in 1975.

He immediately headed south to Miami, where he landed a job as a prosecutor in the major crimes division of the State Attorney’s Office headed by Janet Reno. After four years there, he broke out on his own in 1983 — the beginning of a criminal defense career that would eventually make him one of the most sought after lawyers in Miami.

In 1987, Quinon’s tough, tactical skills in the courtoom won him a lucrative client — Colombian drug lord Carlos Lehder. But he and fellow attorney Ed Shohat ended up losing what turned out to be a hopeless case.

Quinon was also one of the defense attorneys in the notorious Miami River cops-cocaine trafficking case during the late 1980s.

At the time, Quinon told a newspaper reporter that the appeal of defending drug dealers was “vicariously living lives that you only see in movies.” His personal life, he said, was “so boring that it even bores me to talk about it.”