Immigration – Leave to enter. MK was a dissident Iranian politician resident in Paris. She had been excluded from the United Kingdom by the Secretary of State, on the advice of the Foreign Office, on the ground that her presence would not be conducive to the public good. The Supreme Court dismissed the claimants' appeal arising from the Secretary of State's decision and held, amongst other things, that to reject the Foreign Office assessment of the risks to national security, public safety and the rights of others would be to step beyond the proper function of a court of review and would involve rejecting by far the strongest and best qualified evidence before it.