Britain acted illegally, say judges in scathing ruling that upholds Mauritius’s rights and restricts US ability to expand ‘rendition’ air base on Diego Garcia

Britain acted illegally in the way it has exercised territorial control over the Chagos Islands, a UN tribunal has ruled, raising questions over the UK’s claim to sovereignty and offering hope of return to hundreds of evicted islanders.



In a withering judgment, the UK is accused of creating a marine protected area (MPA) to suit its electoral timetable, snubbing the rights of its former colony Mauritius and cosying up to the United States, which has a key military base – allegedly used for the rendition of terrorist suspects – on the largest island, Diego Garcia.

The ruling effectively throws into doubt the UK’s assertion of absolute ownership, restricts the Americans’ ability to expand their facility without Mauritian compliance and boosts the chances of exiled Chagossians being able to return to their homeland.

A partly dissenting opinion from two of the five judges on the permanent court of arbitration at The Hague is even more scathing, stating that “British and American defence interests were put above Mauritius’s rights” both in 1965 when the British Indian Ocean Territory (BIOT) was established and in 2010 when the marine zone, which involves a ban on fishing, was set up.

The ruling, which was made under the 1982 United Nations convention on the law of the sea to which the UK is a signatory, is binding. It torpedoes the status of the MPA and orders the UK and Mauritius to renegotiate. By coincidence, the government this week declared another marine protected area around Pitcairn Island in the southern Pacific.

The five-judge panel found that the creation of the MPA, announced by the former foreign secretary David Miliband in the final months of the last Labour government, breached its obligations to consult nearby Mauritius and illegally deprived it of fishing rights.

The US was “consulted in a timely manner and provided with information”, all five judges state, whereas a meeting with Mauritius in 2009 reminded the tribunal “of ships passing in the night, in which neither side fully engaged with the other regarding fishing rights or the proposal for the MPA”.



The government of Mauritius will view the judgment as a resounding victory, vindication of its ultimate right to sovereignty over the archipelago and confirmation that it must be consulted about future developments on the islands.



The UK has promised to return the Chagos Islands to Mauritius when they are no longer needed for defence purposes.



Mauritius has argued that the UK illegally detached the Chagos archipelago from Mauritius in 1965 – before the country was given its independence – contrary to UN general assembly resolution 1514, which specifically banned the breakup of colonies prior to independence.



The judgment declares: “The United Kingdom’s undertaking to return the Chagos archipelago to Mauritius gives Mauritius an interest in significant decisions that bear upon the possible future uses of the archipelago. Mauritius’ interest is not simply in the eventual return of Chagos archipelago, but also in the condition in which the archipelago will be returned.”

Relations between the UK, Mauritius and the Chagossians have been fraught ever since the 1,500 islanders were removed to make way for the US base in 1971.

The judgment refers to a disputed US telegram that records a meeting with British officials in 2009 in which one is alleged to have said: “BIOT’s former inhabitants would find it difficult, if not impossible, to pursue their claim for resettlement on the islands if the entire Chagos archipelago were a marine reserve”.

The ruling also confirms that in an exchange of notes between Washington and London during 1966 “kept secret at the time, the United States agreed to contribute £5m to the costs of establishing the BIOT, to be paid by waiving United Kingdom payments in respect of joint missile development programmes”.

Prof Philippe Sands QC, of Matrix Chambers, who was lead external counsel for Mauritius, said: “This is a historic and far-reaching judgment: for Mauritius, for Africa, for the international rule of law. It offers hope that Mauritius and Britain will be able to move forward to bring to an end an unhappy legacy of colonialism in the Chagos archipelago and Diego Garcia. It opens the door to a return to legality, in relation to matters of sovereignty and the conservation of a remarkable environmental space.”

Sabrina Jean of the Chagos Refugees Group in the UK said exiled islanders were now focused on the outcome of a study being conducted by the accountants KPMG on behalf of the Foreign Office.

“Our case is fighting for the right of return of the Chagossian community. We are focused on the feasibility study and what was said in it, and they have said that Chagossians could return. It depends on the study, but we are quite confident that a fair resettlement can be done. As we’ve always said, we Chagossians are ready to go.”

If there were to be a fair resettlement offer, she said, some of the Chagossians would definitely wish to return home, while others would want to visit the islands make up their minds.

The main judgment says: “The UK has not been able to provide any convincing explanation for the urgency with which it proclaimed the MPA on 1 April 2010,” and suggests that its “haste” was “dictated by the electoral timetable in the United Kingdom or an anticipated change of government”.

It adds: “Not only did the United Kingdom proceed on the flawed basis that Mauritius had no fishing rights in the territorial sea of the Chagos archipelago, it presumed to conclude – without ever confirming with Mauritius – that the MPA was in Mauritius’ interest.”

Two of the judges, James Kateka and Rüdiger Wolfrum, go further, referring to “language of intimidation” used by the then colonial secretary in the 1960s.

The two judges observe that: “The 1965 excision of the Chagos archipelago from Mauritius shows a complete disregard for the territorial integrity of Mauritius by the United Kingdom, which was the colonial power.

“British and American defence interests were put above Mauritius’ rights. Fast forward to 2010 and one finds a similar disregard of Mauritius’ rights, such as the total ban on fishing in the MPA. These are not accidental happenings.”



In effect, they find that the UK does not have sovereignty because the archipelago should never have been separated from Mauritius. The other three judges say the tribunal does not have jurisdiction to resolve this aspect of the issue.



In 2013, a spokesman for David Miliband told the Guardian: “The marine protected area has been a great step forward and went through all proper government processes.”

A Foreign and Commonwealth Office spokesperson said: “We are pleased that the tribunal found there was no improper motive in the creation of the MPA. There is no question about UK sovereignty in the British Indian Ocean Territory; as the legitimate power, the UK is committed to working with neighbouring states, including Mauritius, to ensure proper conservation management of the marine protected area.”

“We will now work with Mauritius to explore how its fishing ambitions are compatible with conservation in the territory.”

Poisoned waters

The declaration of a Marine Protected Area around remote Indian Ocean atolls must have appeared to the world at large to be an unqualified environmental benefit when first announced by Gordon Brown’s government in 2010.



But in the poisoned diplomatic waters surrounding the Chagos Islands, it only served to arouse suspicions that the colonial power had devised a new excuse for excluding Mauritian fishermen and preventing the return of exiled islanders.

At the heart of UK and US interests in what it known as BIOT (British Indian Ocean Territory) lies the island of Diego Garcia, a military outpost of crucial strategic significance.

BIOT was established in 1965 out of islands claimed by Mauritius. In the early 1970s, the UK government began clearing the plantations, deporting the Chagossians and clearing the land for a naval and air base to be leased to the United States military.

The gradual prising open of official files by this case and other court challenges has revealed a history of Foreign Office calculation and condescension epitomised for critics in the phrase “Man Fridays ” – deployed to undermine the notion that Chagossians were native to the islands.

• This article was amended on 20 March 2015 to clarify that the judges James Kateka and Rüdiger Wolfrum did not dissent from the main judgment in the case.