
The UK has announced it is giving up sovereignty of a remote but strategically important cluster of islands in the Indian Ocean after more than half a century.
The deal – reached after years of negotiations - will see the UK hand over the Chagos Islands to Mauritius in a historic move.
This includes the tropical atoll of Diego Garcia, used by the US government as a military base for its navy ships and long-range bomber aircraft.
The announcement, made in a joint statement by the UK and Mauritian Prime Ministers, ends decades of often fractious negotiations between the two countries.
The US-UK base will remain on Diego Garcia – a key factor enabling the deal to go forward at a time of growing geopolitical rivalries in the region between Western countries, India, and China.
The deal is still subject to finalisation of a treaty, but both sides have promised to complete it as quickly as possible.
"This is a seminal moment in our relationship and a demonstration of our enduring commitment to the peaceful resolution of disputes and the rule of law," the statement from UK Prime Minister Keir Starmer and Mauritius Prime Minister Pravind Jugnauth read.
The leaders also said they were committed "to ensure the long-term, secure and effective operation of the existing base on Diego Garcia which plays a vital role in regional and global security".
The treaty will also "address wrongs of the past and demonstrate the commitment of both parties to support the welfare of Chagossians".
The UK will provide a package of financial support to Mauritius, including annual payments and infrastructure investment.
Mauritius will also be able to begin a programme of resettlement on the Chagos Islands, but not on Diego Garcia.
The Chagos islanders themselves – some in Mauritius and the Seychelles, but others living in Crawley in Sussex – do not speak with one voice on the fate of their homeland.
Some are determined to return to live on the isolated islands, some are more focused on their rights and status in the UK, while others argue that the archipelago’s status should not be resolved by outsiders.
In recent years, the UK has faced rising diplomatic isolation over its claim to what it refers to as the British Indian Ocean Territory, with various United Nations bodies, including its top court and general assembly, overwhelmingly siding with Mauritius and demanding the UK surrender what some have called its "last colony in Africa".
But until very recently, the UK insisted that Mauritius itself had no legitimate claim to the islands.
Tory leadership candidate Tom Tugendhat argued the deal had been "negotiated against Britain's interest" and it was "disgraceful" that such talks had begun under the previous Conservative government.
He called it a "shameful retreat" that leaves "allies exposed", while the former foreign secretary James Cleverly called it a "weak" deal.