The contemptuous ease with which the Johnson-Cummings regime has attempted to cripple parliamentary consideration of alternatives to a no-deal Brexit by proroguing parliament raises serious issues about the remaining value of the UK’s ‘unfixed constitution’. This controversy comes after a prolonged period in which the executive under Theresa May used every micro-institutional weapon to blackmail MPs into accepting its deal. Patrick Dunleavy argues that the UK has slipped into having a failed constitution, where core democratic institutions are contaminated by rigged micro-institutions. The control of power has become dominated by a bunch of executive tricks, and an uncodified ‘constitution’ no longer provides any predictable or worthwhile constraints on government action. Yet it may be only a small step from creating a failed constitution to becoming some version of a failed state.