Some pacific islanders from the British Indian Ocean Territory (BIOT- a British colony) had been forced to leave their islands to make way for a US naval base. A later home sec. drafted an order saying that they would be allowed to return without visas, following a court ruling. However before this could be implemented, the next home sec reversed the policy, claiming he had no need to follow it through since judicial review didn’t apply to policies enacted on monarchical prerogative (as this was). CA said prerogative powers ARE subject to judicial review and that colonial government was not an exempted subject matter. The islanders were allowed to return due to breach of human rights and procedural impropriety (the islanders had been given a legitimate expectation by the initial court and the previous home secretary that they could return).