WASHINGTON -- NATO, finally speaking with one voice on Bosnia, has been sent reeling by fresh allegations of corruption against its Belgian secretary general Willy Claes.


Just as the alliance enters one of the most critical periods in its history, the completion of planning for a Bosnian peace implementation force, furious speculation has again broken out over Claes' political future.


NATO diplomats, worried that his mere presence is weakening the alliance, are now openly questioning how long he can hang on.


"It is terribly debilitating. At a time like this his concentration has to be on the job 100 percent, he can't disappear into private meetings with lawyers and so on," said one alliance diplomat.


NATO diplomatic sources say all attention should be focused on organizing the biggest and most dangerous ground operation ever launched by the military alliance, not on demeaning newspaper headlines.


The allegations against Claes center around a bribery scandal involving the Italian helicopter company Agusta when he was economics minister in 1988, an incident which has convulsed Belgian politics for the last two years.


Four Belgian ministers have resigned since 1994 following accusations of kickbacks paid by Agusta to Claes' Flemish socialist party. So far, there is no suggestion Claes himself received any money and he has always denied any wrongdoing.


The issue pushed its way back to center stage Friday after Belgian media reports said the country's highest constitutional court had recommended to parliament that he face charges on corruption and fraud.


A clearly shaken Claes immediately said he planned to carry on as head of NATO.


"I am totally innocent, I have never done anything wrong," Claes told a news conference following a two-day meeting of NATO defense ministers in the U.S. colonial town of Williamsburg.


But Belgium's press immediately clamored for Claes' head.


"If he is really concerned about NATO's image ... he resigns voluntarily now," wrote one columnist in De Gazet van Aantwerpen, a Flemish-language daily.


"Claes should step down," added Het Laatste Nieuws. "Is there someone who can make him understand this?"


On Monday, a special parliamentary commission began to discuss the Belgian court's report. The 11-member panel will decide on procedure Tuesday.


In Belgium, politicians can only be investigated with parliament's approval.


Under constitutional law, parliament has the right to indict ministers and bring them before the Cour de Cassation, the constitutional court.