

What was meant to be the Labour Government’s flagship foreign policy has now become a judicial spectacle and a political firestorm. In a stunning overnight ruling, the High Court of Justice, King’s Bench Division, issued an emergency interim order suspending the UK’s imminent treaty with Mauritius to surrender sovereignty over the Chagos Archipelago. This is the first time an English court has blocked the conclusion of an international treaty in advance of signature, in a direct challenge to the longstanding doctrine of executive supremacy in foreign affairs.
The immediate cause was a legal action mounted by Bertrice Pompe, a British national of Chagossian origin, who was expelled from Diego Garcia as a baby. She contends that the Starmer Government’s attempt to hand the territory to Mauritius violates fundamental rights and due process, effectively disenfranchising thousands of Chagossians while rewarding a regime with no democratic mandate over the islands. Ms. Pompe’s claim has now forced a full judicial review of the deal, freezing any further diplomatic action.
The Chagos Archipelago is not just another colonial vestige. Diego Garcia, the largest island in the archipelago, is home to one of the most important U.S. military facilities in the world—an enormous joint UK-US base established in the 1970s, hosting long-range bombers, naval assets, and intelligence infrastructure critical to operations across the Middle East, Indo-Pacific, and the Horn of Africa. For decades, the island has served as a launch point for U.S. operations in Iraq and Afghanistan, a surveillance hub in the Indian Ocean, and a keystone of American global reach.
What’s more, Mauritius has steadily deepened its ties with China, attracting significant investment and expanding diplomatic cooperation. This growing relationship raises concerns about Beijing’s influence over the strategically located archipelago.
Mauritius has claimed the islands since independence, but it has never administered them. The claim is historically meaningless: the Chagos Archipelago was deliberately detached from the British Indian Ocean Colony before Mauritius was granted independence in 1968 and has never formed part of Mauritian sovereign territory. The UK retained control, forcibly removing the native Chagossians to clear the way for the joint military base, a historic injustice the courts have recognized but not reversed.
The UK-Mauritius treaty, which was suspended following political backlash, would, in effect, transfer sovereignty to a Mauritian government with no capacity to protect the strategic use of Diego Garcia, and no intention to guarantee the rights or return of the Chagossian people without conditions. The dramatic judicial intervention followed a last-minute leak by the government this week, revealing plans to sign the treaty on May 22—despite widespread belief the deal had been abandoned.
The government’s decision to fast-track the handover was not just morally suspect but geopolitically reckless. It also appears constitutionally dubious. The treaty was scheduled for signature amid Parliamentary recess and just before an expected vote on domestic welfare cuts, suggesting a deliberate attempt to avoid scrutiny. That strategy has failed. The High Court’s intervention is not only a humiliation for Prime Minister Sir Keir Starmer and Foreign Secretary David Lammy but a signal that legal and political institutions are no longer prepared to treat foreign policy as immune from democratic oversight.
The emergency order now forces the government to answer in public for what it tried to deliver in private: the abandonment of strategic territory, the sidelining of British citizens, and the possible weakening of an infrastructure critical to U.S. security.
What began as a rushed and ideological diplomatic offensive now stands as a warning, both to the architects of this misguided deal and to future governments tempted to barter sovereignty behind closed doors.
For the time being, the U.S. also stands to benefit from the judicial ruling, as Washington has narrowly averted the pillaging of its strategic interests—the question is for how long before the Labour government tries again.
Bepi Pezzulli is a Solicitor of the Senior Courts of England and Wales specializing in Governance as well as a Councillor of the Great British PAC. He tweets at @bepipezzulli
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