article_snippet: Maintaining this key the United States relationship is the most important foreign policy challenge facing Britain's prime minister after May 7.
article_snippet: Whether that person is the Conservative party's David Cameron or the opposition Labour party's Ed Miliband makes no difference.
highlights_snippet: Whoever wins May 7 election must answer this question, says Simon Tisdall:
highlights_snippet: Simon Tisdall: Maintaining U.S. relationship is most important foreign policy challenge facing Britain's PM after May 7 .
  