UK High Court blocks deal to return Chagos Islands to Mauritius

An agreement to transfer sovereignty of the Chagos Islands from the United Kingdom back to Mauritius has been paused by a last-minute injunction, prompted by a legal challenge from exiled islanders.

The UK had been set to transfer sovereignty over the Chagos Archipelago in the Indian Ocean, which was separated from Mauritius in 1965 when the latter was still a British colony.

The landmark deal would see the UK retain control of the strategically important Diego Garcia military base under a 99-year lease agreement with the United States.

But in the early hours of Thursday morning, a British High Court judge issued an injunction halting the agreement.

Forced displacement

The legal challenge was brought by two women representing the interests of the Chagossians – the original islanders who were forcibly removed in the 1960s and 70s to make way for the construction of the military base.

Around 2,000 people were displaced, many settling in the UK.

Judge Julian Goose ruled that the UK must maintain its jurisdiction over the British Indian Ocean Territory “until further order,” with a follow-up hearing scheduled for later in the morning.

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The move comes after months of diplomatic wrangling. The UK and Mauritius had reportedly finalised the draft deal in October, but progress stalled due to a change of government in Mauritius and disputes over financial terms.

Some reports have estimated the cost of the deal to the UK at £9 billion (€10.6 billion).

International backing

The deal has seen broad international backing. Both the previous and current US administrations have supported the arrangement, as have the United Nations and the International Court of Justice, which have consistently urged the UK to return the islands to Mauritius.

Handover of Chagos Islands to Mauritius 'not an outright win'

The deal also includes a proposed resettlement fund for displaced Chagossians, though details remain unclear.

UK Prime Minister Keir Starmer had been expected to join a virtual signing ceremony alongside Mauritian officials on Thursday morning.