UK signs £101m-a-year deal to hand over Chagos Islands and lease military base

Sir Keir Starmer has signed a deal to hand the Chagos Islands to Mauritius and lease back a key military base for £101m a year.

The prime minister said the deal was the only way to maintain the base’s long-term future and strengthened the UK’s national security.

Under the terms of the agreement Mauritius would gain sovereignty of the islands from the UK, but allow the US and UK to continue operating a military base on one of the islands, Diego Garcia, for an initial period of 99 years.

The Conservatives described the deal as “an act of national self-harm”, which left the UK “more exposed to China” because of its ties with Mauritius.

The UK signed the agreement after overcoming a last-minute legal challenge brought by two Chagossians.

The UK purchased the islands for £3m in 1968, but Mauritius has argued it was illegally forced to give away the islands in order to get independence from Britain.

The islands were then cleared to make way for a UK-US armed forces base with large groups of Chagossians moving to Mauritius and the Seychelles, or taking up an invitation to settle in England, mainly in Crawley, West Sussex.

The government said it would pay Mauritius an average of £101m a year for 99 years, which Sir Keir said amounted to a “net cost” of £3.4bn after adjusting for factors including inflation.

The prime minister told a news conference the UK had to “act now” or face Mauritian legal action that could interfere with the Diego Garcia base.

Speaking from the UK’s Northwood military headquarters, Sir Keir said: “President Trump has welcomed the deal along with other allies, because they see the strategic importance of this base and that we cannot cede the ground to others who would seek to do us harm.”

He added: “If we did not agree this deal the legal situation would mean that we would not be able to prevent China or any other nation setting up their own bases on the outer islands or carrying out joint exercises near our base.

“No responsible government could let that happen.”

The deal sets a 24-mile buffer around Diego Garcia, where nothing can be built without UK consent.

Foreign military and civilian forces will also be barred from other islands in the archipelago, with the UK retaining a power to veto any access to the islands.

There is also an option to extend the lease by 40 further years, if agreed by both sides.

The treaty comes into effect only after it is approved by both the UK and Mauritian parliaments.

Mauritius Prime Minister Navin Ramgoolam hailed the deal as a “great victory for the Mauritian nation”.

“I have always said we must obtain our sovereignty over the totality of the Chagos, including Diego Garcia,” he said.

“The Chagossians must be able to live once again on their islands.”

US Secretary of State Marco Rubio also welcomed the deal, saying it “secures the long-term, stable and effective operation of the joint US-UK military facility at Diego Garcia, which is critical to regional and global security”.

However, the agreement has attracted strong criticism from opposition politicians in the UK, who have questioned the cost and say an important military base should not be given to a country with close links to China.

Conservative leader Kemi Badenoch said: “Only Keir Starmer’s Labour would negotiate a deal where we’re paying to give something away.

“This is a vital military base. Mauritius is an ally of China.”

Reform UK leader Nigel Farage said: “Keir Starmer cares more about foreign courts than Britain’s national interest.

“Giving Chagos to Mauritius was not necessary and plays into China’s hands.”

It comes after the High Court dismissed a legal challenge, which temporarily blocked the deal when a last-minute court injunction was granted at 02:25.

The legal action was brought by two Chagossian women, Bernadette Dugasse and Bertrice Pompe, who were both born on Diego Garcia, the largest of the islands, and would like to be able to return.

The deal states Mauritius is “free to implement a programme of resettlement” on the islands, excluding Diego Garcia, which is home to the UK-US military base.

In a pre-action letter, lawyers for the two women said the Chagossian people had unlawfully not been given a say in the future of the islands, despite being the native inhabitants.

They also said that they did not trust Mauritius to treat the Chagossians fairly, and that they would face “severe obstacles” as British citizens who do not hold Mauritian nationality, including possible racial discrimination and the loss of the possibility of returning.

Following the court’s decision, Ms Pompe said it was “a very, very sad day” but added: “We are not giving up.”

“We don’t want to give our rights, hand over our rights to Mauritius. We’re not Mauritians,” she said.

On Thursday, representatives of the Chagossian community met Foreign Secretary David Lammy and minister Stephen Doughty, for discussions on the sovereignty of the territory.

In a call immediately after the meeting, Jemmy Simon, from the Chagossian Voices group, told the BBC there was “nothing in there [the deal] that is any good for us”.

“I’m beyond horrified and angry right now.”

“They [the British government] promised to look out for our best interests – absolute rubbish,” she said.

“It is up to Mauritius to decide if we will get to resettle on the outer islands or not, but they don’t have to if they don’t want to.”

However, at a gathering near the Mauritian capital city of Port Louis dozens of Chagossians lit fireworks to celebrate the signing of the deal.

Olivier Bancoult, leader of the Chagos Refugees Group, hailed it as “a historic day for us”.

“For years, talking to our children about Chagos felt like telling them a story about a place we never truly knew – today, they will finally be able to walk the land of their ancestors,” he said.

The Chagos Archipelago was separated from Mauritius in 1965, when Mauritius was still a British colony.

Britain invited the US to build a military base on Diego Garcia and removed thousands of people from their homes on the island and preventing their return.

In recent years, the UK has come under growing international pressure to return the islands to Mauritius, with both the United Nations’ top court and general assembly siding with Mauritius over sovereignty claims.

In late 2022, the previous Conservative government began negotiations over control of the territory but did not reach an agreement by the time it lost power in the 2024 general election.

Additional reporting by Yasine Mohabuth, in Port Louis, Mauritius