Britain's Queen Elizabeth II greets David Cameron, the leader of the Conservative Party, at Buckingham Palace, London, in an audience to invite him to be the next Prime Minister of the United Kingdom, following last week's General Election, Tuesday May 11, 2010. (AP Photo/John Stillwell, Pool)
April 20, 2011 3:22:57 PM PDT
LONDON (AP) - April 20, 2011 --
Prime Minister David Cameron is changing course and plans to wear a formal morning suit with long tails to the royal wedding after all.