Democrats and Republicans on the Senate foreign relations committee are expected to wield their rhetorical swords today in their final duel over John Bolton, the controversial White House nominee for US ambassador to the United Nations.

The battle over Mr Bolton, the undersecretary of state for arms control, has become one of the most contentious issues in President George W. Bush's second term, eclipsed only by an even more vitriolic fight over his judicial nominations. The stakes are high for Mr Bush, who has said he intends to spend the political capital he has earned on Mr Bolton's re-election.