BOISE, Idaho — Under fire from leaders of his own party, Senator Craig of Idaho said yesterday that the only thing he had done wrong was to plead guilty after a police complaint of lewd conduct in a men’s room. He declared, “I am not gay. I never have been gay.”

“I did nothing wrong at the Minneapolis airport,” he said at a news conference with his wife, Suzanne, at his side.

Mr. Craig’s defiant stance came as Senate Republican leaders in Washington called for an ethics committee review into his involvement in a police sting operation this summer in the airport men’s room.

“In the meantime, the leadership is examining other aspects of the case to see if additional action is required,” Senator McConnell and other top GOP lawmakers said in a written statement.

A private group, Citizens for Responsibility and Ethics, also filed a complaint with the ethics committee seeking an investigation into whether Mr. Craig violated Senate rules by engaging in disorderly conduct.

Mr. Craig entered his plea several weeks after an undercover police officer in the airport arrested him and issued a complaint that said the three-term senator had engaged in actions “often used by persons communicating a desire to engage in sexual conduct.”

The airport incident occurred June 11. Mr. Craig signed his plea papers on August 1, and word of the events surfaced Monday. The senator issued a statement Monday night that said, “In hindsight, I should have pled not guilty.”

He repeated that assertion at the news conference. “In June, I overreacted and made a poor decision,” he said. “I chose to plead guilty to a lesser charge in hopes of making it go away. … I did nothing wrong at the Minneapolis airport.”

The conservative three-term senator, who has represented Idaho in Congress for more than a quarter-century, is up for re-election next year.