Ireland's defense minister resigned from his post Thursday after falsely accusing a political rival of running a brothel — and then denying in court that he made the slanderous comment.

Defense Minister Willie O'Dea insisted his sworn statement did not amount to perjury. He retracted it after a journalist produced an audio recording of his brothel claims.

O'Dea — long renowned as one of the country's most verbally combative politicians — survived a parliamentary vote of no confidence Wednesday on strictly partisan lines.

But within hours the Greens, the junior party in Prime Minister Brian Cowen's coalition government, changed their mind and said O'Dea must go because of the questionable ethics of his conduct, compounded by his initial arrogant defense of his actions.

O'Dea made a last plaintive bid to stay in office, going live on national radio Thursday to apologize for what he called "a stupid, silly mistake."

Cowen had sternly defended his friend hours earlier, but accepted his resignation after meeting Green Party leader John Gormley — and determining that O'Dea's continued place in Cabinet could destroy Ireland's 2 1/2-year-old coalition and trigger early elections.

Gormley, who is Ireland's environment minister, said his party could not tolerate "the nature of the attacks and smear of another individual in politics."

Politicians said sentiment moved decisively against O'Dea after his reckless, defamatory comments made against Sinn Fein politician Maurice Quinlivan were broadcast for the first time Thursday on national radio.

O'Dea told a journalist in March 2009 that Quinlivan was operating a brothel in an apartment he owned in O'Dea's power base of Limerick, western Ireland.

Quinlivan sued for defamation, saying he didn't own the property and knew nothing about a brothel operating from it. Police had arrested three Brazilian prostitutes at the property — owned by Quinlivan's brother Nessan, a notorious Irish Republican Army veteran — in January 2009.

O'Dea provided a sworn affidavit denying he had made the comments. This helped him defeat Quinlivan's initial legal efforts.

O'Dea changed his story after a Limerick Chronicle reporter produced an audio recording of O'Dea saying precisely what he had denied saying.

"I suppose I'm going a bit too far when I say this, but I would like to ask Mr. Quinlivan, is the brothel still closed?" O'Dea said on the recording. "There was a house owned by him that was rented out, and they found two ladies of the night operating in there in the last couple of weeks."

In December, two days before Christmas, O'Dea apologized in Dublin High Court and paid Quinlivan undisclosed damages. The affair attracted no attention until national newspapers highlighted it Sunday.

Enda Kenny, leader of the opposition Fine Gael party that brought Wednesday's no-confidence vote, said few people believed O'Dea's claim to have "forgotten" that he branded Quinlivan a pimp. He said the prime minister should never have defended O'Dea in the first place.

"This debacle raises fundamental questions about the (prime minister's) willingness to enforce proper standards of behavior in his government," Kenny said.

O'Dea, 57, has been a lawmaker since 1982 and defense minister since 2004. He has courted controversy before, including when he pointed a handgun at a photographer in 2005 and got into a bar fight in 2007.