The British ambassador to the European Union, Sir Ivan Rogers, has officially resigned. Sir Ivan was appointed by David Cameron in 2013 and was to carry a major role in shaping the Brexit deal in a few months. Sir Ivan chose to resign before negotiations started, allowing the government to find his successor in time, a UK spokesperson told the BBC. a government spokesman told BBC. The former ambassador prompted criticism after the BBC revealed he had privately told ministers that Brexit deal could take 10 years to finalize.