Bertrice Pompe, R (on the application of) v The Secretary of State for Foreign, Commonwealth and Development Affairs

At the permission stage, a judicial review claim must show an arguable ground with a realistic prospect of success. A challenge directed in substance at the terms of an international treaty engages the non-justiciable foreign affairs prerogative. Even where review is theoretically available, decisions involving international relations, defence and security attract an especially broad margin of discretion.

The public sector equality duty in section 149 of the Equality Act 2010 does not apply to decisions given effect by primary legislation, including preparation and promotion of a Bill. Procedural fairness and consultation duties cannot require consultation about rights which the claimants never possessed, particularly where the subject matter is treaty-making and sovereignty. Earlier litigation may prevent substantially identical challenges being reopened.

Two sets of judicial review proceedings were heard together. Bertrice Pompe and Louis Michel Mandarin and Louis Misley Mandarin, British citizens of Chagossian origin, challenged decisions by the Secretary of State concerning the proposed transfer of sovereignty over the British Indian Ocean Territory to Mauritius.

They alleged failures of consultation, irrationality, breach of the public sector equality duty, discrimination contrary to article 14 of the European Convention on Human Rights, procedural unfairness and breach of article 8. The Secretary of State argued that the claims were a collateral attack on an international treaty and that substantially identical issues had already been rejected in earlier Chagos litigation. The issue was whether any ground was arguable with a realistic prospect of success.

1. Permission refused and claims dismissed. The permission threshold was low, but the defendant had established a clear knockout point on each ground. A full hearing would provide no useful benefit.
2. The challenge was in substance directed at the terms of the Treaty, including the fact that Mauritius was given a discretion rather than an obligation to permit resettlement. The making of treaties and the exercise of the foreign relations prerogative were not reviewable in these circumstances. The claims could not be recast as ordinary public law challenges to avoid that conclusion.
3. Alternatively, the grounds were inseparably connected with foreign policy, international political sensitivity, relations with the United States, defence and international security. They therefore attracted an especially broad margin of discretion. The proposed irrationality challenge was also substantially determined by Bancoult (No. 5).
4. No arguable duty to consult arose. Statements expressing an intention to engage did not create a clear and unambiguous promise to consult. Earlier consultations about the marine protected area and resettlement did not establish a settled practice requiring consultation about sovereignty. The Treaty did not remove any existing right of abode or settlement, since the claimants had never possessed such rights.
5. The public sector equality duty under section 149 of the Equality Act 2010 did not apply. The Treaty was to be implemented by primary legislation, and the statutory exclusion for decisions relating to primary legislation included preparation and promotion of the Bill before Parliament.
6. The article 8 and article 14 grounds were unarguable. Article 14 was parasitic, and the claimants could not establish an arguable interference with article 8 based on the loss of rights they had never held. Earlier findings that Convention obligations did not extend to the BIOT remained relevant.
7. No freestanding procedural fairness duty required a referendum, survey or further consultation. The engagement undertaken had provided information about the range of Chagossian views, and the issue had already been determined in Bancoult (No. 5). The application for a costs capping order did not require determination.

The judgment records that permission had previously been refused on the papers by a single judge. The claimants renewed their applications at an oral hearing. No appeal from the present decision is stated.