Boris Johnson's adviser Lee Cain quits Downing Street role after revolt by Carrie Symonds

Boris Johnson was trying to prevent an exodus of Downing Street staff on Wednesday night after a key aide resigned following a public power struggle with the Prime Minister's fiancée Carrie Symonds. Dominic Cummings, Mr Johnson's most senior adviser, was understood to be considering his position following the departure of his former Vote Leave ally Lee Cain as Mr Johnson's director of communications. Mr Cain's resignation prompted frantic late night scenes in No 10 as staff were tasked with ringing colleagues to gauge how many of them might quit if Mr Cummings followed Mr Cain out of the door. It came after reports that Mr Cummings had confronted the Prime Minister in Downing Street after Mr Cain announced he would be leaving at the end of the year. There were even fears that members of the Prime Minister's Brexit negotiation team, including policy adviser Oliver Lewis, could quit in protest.