W80, an armed police officer, shot Jermaine Baker dead in a police operation. Mr Baker was involved in a plot to snatch two individuals from custody. The police had intelligence that the plotters would be in possession of firearms. W80’s account was that during the intervention, Mr Baker’s hands moved quickly up to a shoulder bag on his chest, and fearing for his life and those of his colleagues, W80 fired one shot. No firearm was found in the bag, but an imitation firearm was in the rear of the car.
Following an investigation by the Independent Office for Police Conduct’s (the "IOPCC") predecessor, the Independent Police Complaints Commission (the “IPCC”), the IPCC concluded that W80’s belief that he was in imminent danger was honestly held, but unreasonable, and that W80 therefore had a case to answer for gross misconduct on the basis of the civil law test that any mistake of fact could only be relied upon if it was a reasonable mistake to have made. It sent the report and its recommendation to the Metropolitan Police Service (the “MPS”), as the appropriate authority for misconduct proceedings against W80. The view of the MPS was that the IPCC had been incorrect as a matter of law in applying the civil law test (which looks to whether an honest but mistaken belief is reasonable) as opposed to the criminal law test of self-defence (which looks to whether the belief is honestly held). By this stage, the IPCC had been replaced by the IOPC and after the MPS indicated that it would not follow the IOPC’s recommendation to bring misconduct proceedings against W80, the IOPC directed the MPS to do so. It is that decision which is challenged in this judicial review.

The Secretary of State's Vulnerable Persons Resettlement Scheme (the "Resettlement Scheme") resettles in the UK those vulnerable refugees who have fled the conflict in Syria and who are referred to the scheme by the United Nations High Commissioner for Refugees (the "UNHCR"). The appellants are Palestinian refugees from Syria. The Appellants are outside the remit of the UNHCR because they are registered with the United Nations Relief and Works Agency ("UNRWA"). Whereas UNHCR has a specific mandate to assist refugees by local integration in the country where they are living, or by resettlement in a third country, UNWRA has no such mandate. It follows that in practice, Palestinian refugees cannot take part in the Resettlement Scheme.
The appellants brought judicial review proceedings challenging the lawfulness of the Secretary of State's adoption and operation of the Resettlement Scheme. The ground of challenge directly relevant to this appeal was that the Secretary of State had failed to comply with the PSED because she did not have due regard to the equality needs set out in that section.
The High Court held that the PSED did have extraterritorial effect. The Court of Appeal held that it did not. The Appellants now appeal to the Supreme Court.