Diego Garcia Military Base and British Indian Ocean Territory Bill

Key Points

• Implements the UK–Mauritius agreement on the Chagos Archipelago and Diego Garcia, with provisions that could affect sovereignty and governance of BIOT.
• Lord amendments sought extensive safeguards: a Chagossian sovereignty referendum, recognition of Chagossian rights in UK law, asylum and resettlement considerations, environmental protections, and broad parliamentary oversight (including cost reporting and an inter‑parliamentary committee).
• Commons has largely disagreed with Lords changes—voting to maintain the original bill terms—while several Lords‑inspired safeguards have been debated, accepted in some forms at times in the Lords, and then subject to later disagreement.
• Key policy debates centre on sovereignty over BIOT/Diego Garcia, rights and potential return for Chagossians, how and when treaty payments are made, and how environmental protections and governance are monitored.
• During Committee and Report stages, numerous amendments were withdrawn or defeated (e.g., calls for immediate referenda, consent requirements for payments, and strict orders being parliamentary‑controlled), while others sought cost transparency and joint oversight of implementation; the bill remains subject to inter‑HHouse negotiation.

Progress

The bill has moved from the Commons to the Lords, where amendments were added, debated, and then largely disagreed with by the Commons on 20 January 2026. It is now back in the Lords for consideration of Commons amendments and reasons, with further potential changes and votes expected before final passage.

Voting

In the Commons, MPs voted to disagree with Lords amendments 1, 5 and 6, signalling broad support for keeping the original bill text. Across parties, voting showed mixed positions but a clear pattern of opposition to the Lords’ additional safeguards, while several committee amendments were defeated or withdrawn. The Lords had proposed a wide range of safeguards (e.g., referendum, rights for Chagossians, cost‑of‑the‑treaty disclosures, and order‑making controls), but these have not been accepted in full by the Commons so far.