The Chagos Archipelago is located in the Indian Ocean and was taken over by Britain in 1814 after the Napoleonic Wars. The decolonization process began in the 1960s, and although Mauritius gained independence from British colonial rule, it was unable to reclaim the islands from the U.K. In 2017, with the support of African countries, Mauritius brought the issue of the Chagos Islands to the U.N. agenda. The U.N. General Assembly referred the matter to the International Court of Justice, despite opposition from the U.S., the U.K. and Israel. In 2019, the court ruled that the U.K. should leave the Chagos Islands. The U.N. General Assembly then endorsed this decision. As British professor James Ker-Lindsay said, the ruling represented a significant defeat for the U.K. This decision did not please the British and was met with British resistance. However, as the presiding judge stated, "The U.K. has an obligation to bring an end to its administration of the Chagos Archipelago."
Negotiations began with Mauritius on Nov. 3, 2022. On Oct.3, 2024, the U.K. agreed to hand over the Chagos Islands to Mauritius. However, due to both the elections in Mauritius and the new government, as well as the presidential change in the U.S., they were given a period of review. On May 22, 2025, the agreement concerning the Chagos Archipelago was signed. Accordingly, the U.K. will transfer sovereignty over the Chagos Islands to Mauritius, but the military base on Diego Garcia, the largest of the islands, will remain in their hands for 99 years. In return, they agreed to pay a certain amount of money to Mauritius every year. According to British Prime Minister Keir Starmer, this fee is 3.4 billion pounds ($4.68 billion) in total, but the possibility of 30 billion pounds is also being seriously discussed.
At first, the British objected, but the real opposition came from the U.S., because the military base on Diego Garcia island is one of the most important U.S. military bases in the world. This base has played a critical role in numerous U.S. operations, from Afghanistan to the Middle East, and has great importance, according to Senator John Kennedy. It is said that this is one of the few places in the world where Americans can refuel their submarines. There have been talks recently that it could also be used to bomb Iran.
Kennedy, who made a special speech on the issue in November 2024, stated that a possible deal between the U.K. and Mauritius ending with the U.K.'s ceding sovereignty of the Chagos Islands to Mauritius would be dangerous. Another thing Kennedy regretted was that they had to pay Mauritius to keep Diego Garcia. He wanted this to change, but failed.
In her article dated June 2, 2025, British Shadow Foreign Secretary Priti Patel also emphasized this point at the very beginning. She wrote, “They have given in to the demands of Mauritius,” and added: “They’ve signed up to make you pay a 30 billion pounds 'surrender tax' over 99 years to lease back our military base on Diego Garcia, with the bill to the British taxpayer rising every single year ... As well as the annual lease payments for 99 years, Labour has signed up to give Mauritius 45 million pounds a year for 25 years.”
Moreover, while the British and Americans were previously responsible for the security of the island and its surroundings, this responsibility will now fall on Mauritius. Just as the senator had mentioned months ago, Patel also drew attention to this issue. They argue that vessels used by foreign powers can partner with Mauritius, a country that’s friendly with Russia and China, and enter waters in the vicinity of Diego Garcia. So, foreign spies and agents can get closer to the base. And the fact that this deal was signed just days after Mauritius signed a new partnership with President Vladimir Putin’s Russia makes opponents extremely nervous. The fact that Mauritius will now know about the activity in Diego Garcia could lead to a leak.
It is said that China has been pleased with these developments because it will surely increase its influence over Mauritius, and this has become an issue in the U.K.'s politics.
Speaking on behalf of the government when the issue was discussed in the House of Commons on Dec. 2, 2024, Labour lawmaker Luke Pollard said nothing about the criticisms and concerns about China made by U.S. Secretary of State Marco Rubio and Tory lawmaker James Cartlidge. On June 5, the Conservatives questioned Foreign Secretary David Lammy for not making a statement in Parliament and not answering questions. For months, Labour’s failure to say anything convincing on Chinese influence has been weighing heavily on them. According to Patel, 41 questions have remained unanswered.
Although Nigel Farage, leader of Reform U.K. and the frontrunner in the latest polls, is now focusing more on immigration and the burqa ban than on the Chagos issue, he was among those who criticized the agreement at the time for its connection to China. Farage pointed out that although 99 years may seem like a long time, there was once a 50-year agreement made with China regarding Hong Kong, but before the agreement expired, China broke it and began acting as it pleased. This is also a point worth considering.
Especially when you consider that something Pollard could not answer in December has now become true. At that time, he was asked whether they would have to pay if Mauritius wanted more money, but he did not answer. In the meantime, their acceptance of Mauritius’ additional demands was one of the reasons for the opposition’s reaction. When the criticism here is proven right, the possibility that the concern about China will also be proven right makes itself felt stronger. The fact that China enthusiastically hailed this deal and the Mauritian Prime Minister Navinchandra Ramgoolam boasted of a "great victory" fired this feeling up.
On Dec. 5, the House of Lords also took up the issue, with Lord David Howell of Guildford reporting that he had witnessed the Chinese showing great interest in the issue. Mauritius is the first African country with which China has signed a free trade agreement. The World Economic Forum published an analysis of the issue in 2021, noting that Mauritius already plays a significant role as an investment entrepot in Africa and that, as China develops plans for a digital currency, Mauritius could eventually lead Africa in this area.
During the recent Iran-Israel war, the China-Mauritius alliance came to the fore in British politics. On June 19-20, the opposition stated that if they wanted to strike Iran, they had to first inform China's ally, Mauritius, and described this as a "national disgrace."
Many British opponents have described the Chagos Treaty as a “betrayal” and have described Starmer as “the worst negotiator in history.” They claim to pay Mauritius 3.4 billion pounds to take "British territory," and it could be "up to 10 times that amount.”
According to opponents, Labour does this to “please lefty lawyers.” They interpret it as an effort to recover the shame of the colonial past. Penny Mordaunt, a prominent figure among the Tories, said the following: “In trying to atone for colonial ‘wrongs of the past,’ we’re actually enabling China’s colonial future.” On the other hand, Labour rightly points out that the Tories started the negotiations first and argues that if there was a mistake, it was theirs. Labour sees it as important that Diego Garcia be given a legal basis through a treaty.
In the House of Commons on June 11, Tory leader Kemi Badenoch asked: "Because of his terrible Chagos deal, Mauritius is scrapping income tax. Why on earth should the British taxpayer pay 30 billion pounds for tax cuts in Mauritius?"
Starmer, focusing on Diego Carlos instead of giving a direct answer, said that: “Diego Garcia is a vital intelligence and strategic capability, and it is absolutely clear that legal uncertainty would compromise it in very short order. That is why the Conservatives started the negotiations in relation to it.” Before this confrontation, the Tories, led by Priti Patel, made a last-ditch attempt and introduced a bill to protect their sovereignty over Chagos, which also stipulated that no payments should be made to Mauritius. But the bill was rejected on June 13, which Patel said was a betrayal. Another bill regarding the issue was proposed by the Tories and rejected by Labour on June 20.
So the financial burden is obvious. In the long term, it is possible for China to benefit from the deal. It’s also clear that the loss of territory is a setback for the British. The government cannot satisfactorily explain or refute these points. However, the opposition also struggles to adequately address the colonial history of holding territory in the Indian Ocean. Attempting to claim distant lands solely on the basis of “security” undermines their accusations against Russia and even makes them appear hypocritical.
It’s also certain that the British possession of Chagos is of no benefit to the world. If they are truly concerned about their security, they should focus on restraining Israel, which has carried out terrorist attacks against them in the past, is currently destabilizing West Asia, and remains a significant financial burden and historical stain on Britain.
