Diego Garcia Military Base and British Indian Ocean Territory Bill: motion to disagree with Lords Amendment 1
344
Ayes
—
182
Noes
Passed · Government won
121 did not vote
Analysis
Commons
Commons
**What happened** On 20 January 2026, the House of Commons voted by 344 to 182 to disagree with Lords Amendment 1 to the Diego Garcia Military Base and British Indian Ocean Territory Bill. The vote meant that MPs rejected a modification introduced by the House of Lords and restored the government's original position on the legislation. The Bill concerns a treaty between the United Kingdom and Mauritius governing the future of the Diego Garcia military base in the British Indian Ocean Territory, and the Commons vote was one of several on the same day in which the government overrode a series of Lords amendments to the legislation. **Why it matters** The Bill, if enacted, would give legal effect to a treaty granting Mauritius sovereignty over the Chagos Islands while securing the continued operation of the joint US-UK military base on Diego Garcia for 99 years. The government argues that without the treaty, the legal basis for base operations would be seriously undermined, with potential for court-ordered provisional measures to disrupt access by air and sea and compromise sensitive operations. Rejecting Lords Amendment 1 clears one of the final legislative hurdles before the treaty can come into force, affecting UK national security arrangements, the position of Chagossian communities, and the financial commitments associated with a long-term payment schedule to Mauritius. **The politics** The vote divided almost entirely along party lines, with 334 Labour and Labour Co-operative MPs voting in favour alongside a handful of Independents and smaller party members, while 100 Conservatives, 63 Liberal Democrats, 7 Reform UK members, and 5 Democratic Unionist Party MPs voted against. Just two Labour MPs voted no. The debate was dominated by Conservative interventions citing a statement by US President Donald Trump, made the previous evening, expressing opposition to the deal, which placed the government on the defensive. The government maintained that earlier endorsements from the Trump administration remained the relevant position and that engagement with Washington was continuing.
Voting Aye meant
Support rejecting the Lords amendment, backing the government's deal with Mauritius as negotiated without additional notification requirements that could constrain military operations at Diego Garcia
Voting No meant
Support keeping the Lords amendment, arguing it provides important safeguards or alternatively opposing the entire deal as a surrender of British sovereignty that weakens the strategic value of the base
526 voting MPs. Each dot is one vote; left-to-right by party. Grey dots in the centre are the 121 who did not vote.
Aye
No
Absent
Labour PartyWhipped Aye
297
2
63
Conservative and Unionist PartyWhipped No
0
100
16
Liberal DemocratsWhipped No
0
63
9
Labour and Co-operative PartyWhipped Aye
37
0
5
Independent
6
4
3
Scottish National Party
0
0
9
Reform UKWhipped No
0
7
1
Sinn Féin
0
0
7
Democratic Unionist PartyWhipped No
0
5
—
Green Party of England and WalesWhipped Aye
3
0
1
Plaid Cymru
0
0
4
Social Democratic and Labour Party
1
0
1
Alliance Party of Northern Ireland
0
0
1
Speaker
0
0
1
Traditional Unionist Voice
0
1
—
Ulster Unionist Party
0
1
—
Your Party
1
0
—
As government minister, defended the treaty as vital to national security, emphasizing the base's protection for 99 years, robust safeguards against adversaries, and backing from allies including the US despite Trump's morning criticism; rejected Lords amendments as unnecessary or politically motivated.Labour · Voted aye · Read full speech (7,050 words) →
Led opposition arguing the deal surrenders British sovereignty for £35 billion with no credible reason, especially after President Trump explicitly rejected it; called for withdrawal of the Bill and demanded transparency on costs and protection of Chagossian self-determination rights.Conservative · Voted no · Read full speech (2,310 words) →
Challenged the government's reliance on US support by pointing out Trump's public rejection of the deal that morning; questioned how the government can justify proceeding without addressing fundamental changes in the US position.Conservative · Voted no · Read full speech (388 words) →
Argued the legal justifications (ICJ judgment, UNCLOS, ITU) had fallen apart under scrutiny; criticised the government for rushing through legislation despite lack of compelling reasons and demanded a pause to consult the now-sceptical US Administration.Conservative · Voted no · Read full speech (1,316 words) →
Supported Lords amendments on cost transparency, environmental durability, and Chagossian self-determination; argued the amendments provide legitimate safeguards and called for government pause given changing geopolitical circumstances, particularly US position shift.Liberal Democrat · Voted no · Read full speech (1,368 words) →
Expressed concern that paying for something the UK owns lacks rationale; called for referendum on Chagossian return rather than surveys, and urged pause to comply with UN Committee on the Elimination of Racial Discrimination and respond to US position change.Labour · Voted no · Read full speech (837 words) →
Defended the treaty as securing critical military assets for 99 years with full operational freedom; argued Lords amendments are unnecessary as international law and joint commissions already address contingencies; rejected claims that social media posts should drive long-term security decisions.Labour · Voted aye · Read full speech (1,255 words) →
Suggested material changes in circumstances (Trump's stance) warrant pausing implementation; implied the previous Conservative Government would never have accepted such a deal given current US opposition.Conservative · Voted no · Read full speech (92 words) →
Sources
Division dataUK Parliament Votes API
DebateHansard · Commons
Stance analysisAI analysis · Claude 4.x
LicenceOpen Parliament Licence v3.0