Factbox - Senior British officials with EU experience who have left their posts

British Prime Minister Theresa May has appointed a senior career diplomat as her envoy to the European Union, replacing an official who criticised the government's Brexit strategy in his resignation letter. Tim Barrow, political director at the Foreign Office, will replace Ivan Rogers. Government officials say that Barrow is "a seasoned and tough negotiator, with extensive experience of securing UK objectives in Brussels" and will complement what they say are teams with strong EU knowledge based