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

Idaho Republican Senator Larry Craig held a news conference yesterday and said that he will resign with effect from 30 September.

The announcement comes just five days after the disclosure that he had pleaded guilty on 1 August to a reduced misdemeanour charge arising out of his arrest on 11 June at the Minneapolis airport.

The three-term 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 in Washington.

Craig has been out of public view since Tuesday, but sources in Idaho said he spent Friday making calls to top party officials, gauging their support. There has been virtually no support publicly.

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

Republican politicians, hoping to get the embarrassment to the party behind them quickly, stripped Craig of leadership posts and called for an investigation of his actions by the Senate Ethics Committee last week.

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

The senator, 62, has represented Idaho in Congress for more than a quarter of a century and was up for re-election next year.

Senate Minority Leader Mitch McConnell called Craig's conduct "unforgivable" and acknowledged that many in the rank and file thought he should resign.

Meanwhile, President George Bush has announced that press secretary Tony Snow, who has waged a battle with cancer while in the White House, will resign and be replaced by his deputy, Dana Perino, on 14 September.

"It's been a joy to watch him spar with you, " Bush told the White House press corps in the briefing room.

Mr Snow said cancer was not the reason he was stepping down.

Instead, the father of three said he can earn far more on the speechmaking circuit than from the White House."I ran out of money, " he said.