Members of the House of Lords are set to continue their detailed scrutiny of the Diego Garcia Military Base and British Indian Ocean Territory Bill, as it enters the report stage on Monday 5 January.
The proposed legislation is designed to give effect in UK law to key elements of a treaty signed in May 2025 between the United Kingdom and Mauritius.
The agreement sets out the future status of the Chagos Archipelago, including the strategically significant joint US–UK military base on Diego Garcia, the largest island in the archipelago.
Under the bill, the UK would formally end its sovereignty over the Chagos Archipelago while introducing a series of consequential changes to British nationality law.
At the same time, the legislation would ensure the continued operation and administration of the existing joint United States–United Kingdom military base on Diego Garcia.
Peers are expected to examine the legal, constitutional and strategic implications of the bill in detail, with particular attention on the transfer of sovereignty, the future governance arrangements for the territory and the long-term status of the military base.
The outcome of the Lords’ scrutiny will be closely watched, given the bill’s significance for UK foreign policy, defence interests and its relationship with Mauritius.
