A divisionDivision No. 318 · Monday, 20 October 2025· Commons· Defence and Foreign Affairs

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

320Ayes
171Noes
Carried · majority 149 · Government won
159 did not vote
Aye317No173DID NOT VOTE · 159

650 Members · Aye 320 · No 171 · DNV 159 · grey dots in centre are abstentions

Analysis
Commons

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. 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 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.

Voting Aye meant
Support passing the Bill and proceeding with the sovereignty transfer to Mauritius, backing the government's treaty to secure the long-term future of the Diego Garcia military base
Voting No meant
Oppose the Bill in its current form, arguing the government should first publish legal advice and risk assessments before ceding British sovereignty over the territory
§ 01Who voted how.491 voting Members · 159 absent

Each row is one party. The stacked bar gives the within-party split of Aye / No / Absent; the columns on the right give the raw counts. The whip column shows the published party position — “Free vote” means the whip was formally removed for this division.

Party
Whip
Aye / No / Abs
Aye
No
Abs
Labour Party
Whipped Aye
272
0
89
Conservative and Unionist Party
Whipped No
0
95
21
Liberal Democrats
Whipped No
0
63
9
Labour and Co-operative Party
Whipped Aye
31
0
11
Independent
5
3
5
Scottish National Party
0
0
9
Reform UK
Whipped No
0
7
1
Sinn Féin
0
0
7
Democratic Unionist Party
Whipped No
0
3
2
Green Party of England and Wales
Whipped Aye
3
0
1
Plaid Cymru
Whipped Aye
4
0
0
Social Democratic and Labour Party
1
0
1
Alliance Party of Northern Ireland
0
0
1
Restore Britain
0
0
1
Speaker
0
0
1
Traditional Unionist Voice
0
1
0
Ulster Unionist Party
0
1
0
Your Party
1
0
0

Source · Hansard · UK Parliament Votes API · whip status from announced positions; “free vote” indicates the whip was formally removed

§ 02From the debate.6 principal speakers
Wendy MortonOpposedAldridge-Brownhills
Opposes the Bill as a £35 billion 'surrender' that compromises UK security, fails to protect Chagossian rights, and lacks legal justification; amendments seek transparency on costs, legal advice, and parliamentary control over payments and the marine protected area.Conservative · Voted no · Read full speech (5,114 words)
Stephen DoughtySupportiveCardiff South and Penarth
Defends the treaty as protecting UK security interests and achieving what Conservative negotiations could not; challenges opposition claims as misinformation and argues the US and allies support the deal.Labour · Voted aye · Read full speech (4,910 words)
Dr Al PinkertonOpposedSurrey Heath
Supports amendments requiring referendum on self-determination for Chagossians, robust reporting on marine protection and expenditure, and consultation with Chagossian communities to address historical injustices.Liberal Democrat · Voted no · Read full speech (2,728 words)
Mr Calvin BaileySupportiveLeyton and Wanstead
Characterises opposition amendments as 'wrecking amendments' designed to undermine international commitments and credibility; opposes referendums on foreign policy as demonstrated failure.Labour · Voted aye · Read full speech (937 words)
Stuart AndersonOpposedSouth Shropshire
Argues ceding Diego Garcia is a 'monumental strategic error' given China's rising military capability, growing Chinese submarine presence in Indo-Pacific, and decline of UK armed forces; base is essential strategic foothold.Conservative · Voted no · Read full speech (740 words)
Sir Edward LeighOpposedGainsborough
Supports advisory referendum for UK-based Chagossians on the treaty; frames it as moderate and sensible proposal.Conservative · Voted no · Read full speech (1,140 words)
§ 03Related divisions.Same topic · recent
Sources
Division dataUK Parliament Votes API
DebateHansard · Commons
Stance analysisAI analysis · Claude 4.x
LicenceOpen Parliament Licence v3.0