The White House yesterday bowed to the political realities imposed by the new Democratic Congress when it accepted John Bolton's resignation as ambassador to the United Nations, ending his combative, controversial tenure.

His departure marks the second high-profile resignation of Mr Bush's long-serving foreign policy team after the November mid-term elections. Tony Snow, White House spokesman, admitted defeat, saying it was "pretty obvious" he was not going to get the votes from the Senate foreign relations committee.