MINNEAPOLIS — Idaho Republican Senator Larry Craig will resign from the Senate amid a furor over his arrest and guilty plea in a police sex sting in an airport men's room, Republican officials said Friday.

Craig will announce at a news conference in Boise on Saturday morning that he will resign effective Sept. 30, three state Republican party officials said, speaking on condition of anonymity.

The announcement follows by just five days the disclosure that he had pleaded guilty Aug. 1 to a reduced misdemeanour charge arising from his arrest June 11 at the Minneapolis airport.

The three-term Republican senator had maintained that he did nothing wrong except for making the guilty plea without consulting a lawyer. But he found almost no support among Republicans in his home state or Washington.

Idaho Gov. C.L. (Butch) Otter appeared Friday to have already settled on a successor: Lt.-Gov. Jim Risch, according to several Republicans familiar with internal deliberations.

Craig has been out of public view since Tuesday, but Republican sources in Idaho said he spent Friday making calls to top party officials, including the governor, gauging their support.

There has been virtually none publicly.

Asked Friday at the White House if the senator should resign, President George W. Bush said nothing and walked off stage.

Republican officeholders and party leaders maintained a steady drumbeat of actions and words aimed at persuading Craig to vacate his Senate seat.

Republican legislators, hoping to get the embarrassment to the party behind them quickly, stripped Craig of leadership posts on Wednesday, one day after they called for an investigation of Craig's actions by the Senate Ethics Committee. Craig complied with the request.

With his wife, Suzanne, at his side, he said he had kept the incident from aides, friends and family and later pleaded guilty "in hopes of making it go away."