Labour MPs including Emily Thornberry join growing chorus of criticism over the Chagos deal, questioning its legitimacy and long-term impact.
The Chagos Islands treaty, formally transferring sovereignty of the British Indian Ocean Territory (BIOT) to Mauritius, has triggered an increasingly vocal backlash from within the Labour Party, as senior MPs express doubts over the deal’s transparency, environmental guarantees, and its treatment of the Chagossian community.
In a combative session of the Foreign Affairs Committee last week (23 June), Labour’s own Emily Thornberry, Chair of the Committee, challenged Foreign Office officials over what she called a lack of democratic oversight and insufficient safeguards.
“Do you not think that the CRAG process is something from the 19th century and ought to be thrown in the Thames so that we can have a little democracy in this place by having a vote and a debate when treaties are signed?” Thornberry asked in Q6, referring to the Constitutional Reform and Governance Act 2010, which governs parliamentary scrutiny of treaties.
Environmental Alarm Bells
Thornberry also raised urgent concerns about the ecological vulnerability of the archipelago—widely considered one of the last untouched marine ecosystems in the world.
“What concerns me is this: are we going to be handing over these islands before there is in place some form of protection for the wildlife on these islands?” she asked at Q69.
Pressing officials on whether there might be a dangerous delay between the handover and the introduction of environmental enforcement, she warned:
“Might there be a gap during which time the Chinese trawlers turn up and grab all the fish?” (Q72)
She also demanded clarity on concrete funding mechanisms:
“Is there going to be a ringfenced fund that is going to be given by Britain to Mauritius for the protection of the environment and wildlife on these islands?” (Q64)
In an earlier Commons debate, Thornberry highlighted the global environmental importance of the area:
“At a time when our oceans have never been under such stress, the British Indian Ocean Territory is one of the last ocean wildernesses in the world, and tuna trawlers are lining up on the boundary of the no-take zone…”
National Security and Sovereignty Questions
Another core concern centred on the legal and operational guarantees for Diego Garcia, the joint US-UK military base. Thornberry voiced worries about future law enforcement capacity and the reliability of Mauritius in upholding maritime protections.
“So at the moment we are taking it on trust that Mauritius will have a patrol vehicle outside the 12-nautical-mile limit?” she asked pointedly in Q68.
There were also frustrations about timelines and vagueness in answers from Minister Stephen Doughty and Foreign Office Director Peter Candler.
“I am just worried that this is not going to work… and that there will not be a framework in place…” she said in Q76.
Labour’s Peter Lamb MP: ‘Very Disappointing’ and Lacking Legal Certainty
Beyond the committee room, Labour’s Peter Lamb MP, who represents a significant Chagossian population in Crawley, has also criticised the deal in public and parliamentary fora.
In January, he noted that “no engagement had taken place with the Chagossian community” during the negotiations. In May, he called the treaty “very disappointing”, highlighting that it provided “none of the legal certainties required to guarantee Chagossians—particularly those resident in the UK—the ability to access the islands or for permanent habitation to be possible.”
In the Commons, Lamb demanded clarity on what he should tell his constituents:
“What should I tell my Chagossian constituents, when they ask the moral basis upon which the UK is ignoring their right to self‑determination…”
He was later quoted in media reports (including The Telegraph) denouncing the deal as the “worst thing” the Labour Party had done—an extraordinary rebuke from within party ranks.
Cabinet-Level Disquiet and Comparisons to Historical Blunders
According to The Guardian, the Chagos agreement has also caused disquiet at the cabinet level, with two ministers privately expressing concerns about its cost amid wider public spending pressures.
One former Labour adviser told the paper the treaty had the potential to become “a totemic issue akin to Gordon Brown selling half the UK’s gold reserves.” Another branded the deal “a catastrophic error”, arguing that the UK should now exit the process altogether.
“The best way to solve it now and save face is to pull out and say: ‘We tried to be constructive, tried to support the rules-based order, but Mauritius has been completely unreasonable and now it will never be returned.’”
Growing Rift Inside Labour
What Labour tried to sell as a foreign policy win for the government and a demonstration of commitment to international law is now turning into a divisive issue within the Labour Party itself. Thornberry’s intervention signals that even those in leadership roles are no longer convinced the process is sound.
As scrutiny intensifies, from parliamentary committees, grassroots campaigners, and media outlets, the government faces renewed pressure to clarify the treaty’s terms, protect UK strategic interests, and ensure the long-denied rights of the Chagossian people are finally honoured.
A legal battle to ensure Chagossians are lawfully consulted before the UK Government signs away sovereignty of their homeland has cleared its major first hurdle in the High Court last week.
The Judicial Review, launched by Chagossian claimant Louis Misley Mandarin with support from the Great British PAC, has been formally accepted by the court and granted an expedited timetable.
This means the Government must now file its legal defence by 4 July, drastically shortening its usual 28-day window. A High Court judge is expected to review the matter around 11 July, potentially triggering a full hearing by the end of July.
Claire Bullivant, CEO of the Great British PAC, said:
“This is a huge step forward. The courts have recognised the urgency and importance of this case. We now call on Parliament to suspend any process related to Chagos sovereignty until the Court has ruled. Justice demands no less.”
For full transcript and video of the Foreign Affairs Committee session (23 June 2025), visit:
https://committees.parliament.uk/event/24636/formal-meeting-oral-evidence-session/
Sources:
- The Guardian: Chagos deal triggers backlash inside Labour
- Hansard Society: Treaty Scrutiny and the CRAG Process
- Labour MP condemns Chagos deal as ‘worst thing’ party has ever done: https://www.telegraph.co.uk/news/2025/02/10/labour-mp-peter-lamb-condemns-chagos-deal-worst-thing/
