Freedom of movement is one of the 'red lines' that preclude Britain's continuing membership of the Single Market: the PM believes the referendum was a clear rejection of the principle. But could the UK deploy an 'emergency brake' at regional (rather than national) level to help manage EU migration and thereby qualify for European Economic Area membership? Catherine Barnard and Sarah Fraser Butlin (University of Cambridge) look at how it might be possible to allay Leavers’ fears
