Diego Garcia Military Base and British Indian Ocean Territory Bill Committee: Amendment 9

**What happened:** On 20 October 2025, MPs voted on Amendment 9 to the Diego Garcia Military Base and British Indian Ocean Territory Bill during its Committee stage. The amendment, which sought enhanced parliamentary oversight or modified terms for the military base arrangements, was defeated by 319 votes to 83. **Why it matters:** The Diego Garcia Bill concerns the legal framework governing the UK's military base on Diego Garcia, part of the British Indian Ocean Territory, and relates to the broader treaty negotiated with Mauritius over sovereignty of the Chagos Islands. Amendment 9 aimed to alter the terms under which the base would operate, likely by introducing greater scrutiny mechanisms or revised conditions. Its defeat means the government's preferred framework for the base arrangements proceeds without the additional constraints or oversight provisions the amendment would have introduced. **The politics:** The vote saw an unusual cross-party coalition of 83 MPs supporting the amendment, drawn mainly from the Liberal Democrats (63 votes), alongside smaller contributions from Reform UK, Plaid Cymru, the Democratic Unionist Party, the Scottish National Party, and a handful of Conservatives and Independents. Labour and the Co-operative Party MPs voted solidly against, providing the 319 No votes. Notably, the overwhelming majority of Conservative MPs were absent rather than voting against the amendment, a pattern that recurred across several divisions on this bill the same day. The result mirrors closely the pattern of other amendments to the same bill defeated on the same date.