Diego Garcia Military Base and British Indian Ocean Territory Bill

There was a further debate on the Bill in a Committee of the Whole House on Monday 20 October 2025.

The Bill seeks to implement the Treaty between  Mauritius and the UK concerning the Chagos Archipelago including Diego Garcia, terminating UK sovereignty over the British Indian Ocean Territory (BIOT) in domestic law and amending legislation on nationality.

There were four amendments selected for debate and votes:

Amendment 7, which would require the Secretary of State to present a memorandum to Parliament on the obligations under international law which require the UK to cede sovereignty of the British Indian Ocean Territory to the Government of Mauritius. Ayes 174, Noes 321

Amendment 9, which would require that the Government undertake negotiations with Mauritius on a Chagossian right of return and on a referendum, with a report laid before Parliament on the outcome of the negotiations. Ayes 83, Noes 319.

Clause 2, on the dissolution of the British Indian Ocean Territory. Ayes 318, Noes 174

New Clause 1, which requires parliamentary approval for any payment by the UK Government to the Government of Mauritius under the Treaty. Ayes 172 Noes 322

The motion was read that the Bill be read a third time and passed: Ayes 320, Noes 171. The Bill will now go to the House of Lords for further consideration and scrutiny.