Diego Garcia Military Base and British Indian Ocean Territory Bill: Third Reading

What happened: The House of Commons gave final approval to the Diego Garcia Military Base and British Indian Ocean Territory Bill on 20 October 2025, passing it at Third Reading by 320 votes to 171. Third Reading is the final stage at which the Commons votes on the complete text of a bill before it proceeds to the House of Lords. The government, which backed the bill, secured a comfortable majority of 149 votes.

Why it matters: The bill provides the legislative framework for arrangements governing the Diego Garcia military base in the British Indian Ocean Territory (BIOT). Diego Garcia hosts a strategically significant joint UK-US military installation in the Indian Ocean. The legislation forms part of a broader diplomatic process regarding the future of the territory, which has been the subject of negotiations touching on sovereignty, the rights of the Chagossian people who were displaced from the islands, and the continued operation of the base. Passing the bill advances the government's stated objective of placing the base's legal footing on a secure and internationally recognised basis.

The politics: The vote divided sharply along party lines. All Labour and Labour and Co-operative MPs who voted supported the bill, while Conservatives, Liberal Democrats, Reform UK, and the Democratic Unionist Party voted unanimously against. Plaid Cymru and the Green Party, parties that might have been expected to oppose the bill on anti-colonial grounds, instead voted in favour, representing a cross-party grouping on the government's side. The debate generated significant controversy earlier in the same day, with multiple amendment votes failing before the bill's final passage, suggesting strong and organised opposition that nonetheless fell well short of the government's parliamentary majority.