Overview

• The UK has formally ceded sovereignty of the Chagos Islands to Mauritius while retaining a 99-year lease on the Diego Garcia military base, critical to UK-US defence operations.
• The High Court initially issued an emergency injunction blocking the treaty signing, citing a legal challenge by Chagossian Bertrice Pompe over human rights concerns.
• Judge Martin Chamberlain later lifted the injunction, ruling that delaying the deal would harm the UK's national and public interests.
• The agreement follows a 2019 International Court of Justice advisory opinion and extensive bilateral negotiations initiated by the Conservative government in 2022 and concluded by Labour in 2025.
• Critics warn the deal could increase China's influence in the Indian Ocean region, while supporters argue it ensures the strategic base's functionality and addresses international legal obligations.