In a radio interview, Secretary-General Claude Gueant -- Nicolas Sarkozy's chief of staff -- said a threat to walk out of the Sept. 24-25 G20 meeting in Pittsburgh should be taken "very seriously," The Times of London reported Monday.
"The head of state is extremely determined as he was at the G20 in London a few months ago when he pushed for his proposals on tax havens to be agreed," Gueant said.
Britain, Germany and France have expressed dismay over bank bonus checks that encourage risky financial deals.
But, finding an international system to deal with bank compensation is difficult. British Chancellor of the Exchequer Alistair Darling said a French proposal to have bonus checks returned if the deals backfired within three years was "unenforceable."
Still, "I hope we are going to enter an era where we don't have again a situation where people are being rewarded for reckless behavior," Darling said.
Sarkozy also threatened to walk out of April's G20 meeting in London to pressure leaders into dealing with international tax havens.