Asylum seekers arriving on the British-owned archipelago will be shipped to St Helena, another UK territory more than 5,000 miles away

Sir Keir Starmer has agreed a Rwanda-style deal to deport migrants who arrive in the Chagos Islands on small boats, The Telegraph can reveal.

Asylum seekers arriving in the British-owned archipelago will be deported to St Helena, another UK territory more than 5,000 miles away in the Atlantic Ocean.

Sir Keir provoked fury earlier this month when he agreed to sign away the Chagos Islands to Mauritius.

MPs said the “pathetic” decision would harm British interests abroad and the Government had succumbed to legal pressure from the UN.

In a decision which risks sparking further controversy, it has emerged that St Helena has been given £6 million in funding to house any migrants that arrive on the Chagos Islands until the Mauritius deal is finalised.

The migrant agreement bears similarity to the deal with Rwanda struck by the previous Conservative government, which Sir Keir described as “completely wrong” and “immoral”.

One of the most remote places on Earth

Islanders on St Helena, a tiny island of less than 4,500 people with one hospital, also said they were not consulted about the agreement.

Migrant boats are a major problem in the Chagos Islands, which lie in the middle of the Indian Ocean and are home to the Diego Garcia air base, which is jointly run with the US.

Since 2021, hundreds of Sri Lankan migrants have arrived on the archipelago, claiming asylum from political persecution in their home country.

Foreign Office sources said the migrants threatened the operation of the air base, which is used by the US for bombing runs to the Middle East. It is set to remain under UK-US command even after Mauritius takes control of the islands.

Many migrants who have arrived since 2021 have been settled in temporary camps and are challenging their detention in court.

Under the terms of the latest deal, any further migrants that arrive before the transfer of the Chagos Islands to Mauritius will be deported to St Helena, another overseas territory on the other side of Africa.

The island is one of the most remote places on Earth and famously served as the location of Napoleon’s second exile from France after the Battle of Waterloo in 1815.

In return, the government of St Helena has received £6.65 million in Treasury funding, which it plans to spend on dealing with its healthcare backlog.

Migrants being deported to St Helena will be security screened before deportation, and arrivals could continue for 18 months, or as long as it takes for the Mauritius agreement to be finalised.

The deal is likely to be controversial in Westminster after Sir Keir cancelled the UK’s similar deal with Rwanda on his first day in office.

Under the terms of that deal, the UK would pay Rwanda £370 million over five years to resettle migrants, but Labour called it “immoral” and campaigned on a promise to scrap it.

Sir Keir will likely now come under pressure to explain how the new deal to send migrants to St Helena in exchange for funding differs from the Conservative plan.

The Prime Minister has also been accused of abandoning the 14 British overseas territories, which include the Falkland Islands and Gibraltar.

Islanders on St Helena have been left “reeling” by the migrant decision, which they say they were not consulted about before a low-key announcement by chief minister Julie Thomas on Wednesday.

The Foreign Office had made no public statement about the deal until approached by The Telegraph.

Andrew Turner, a St Helena councillor, said: “We are a very small island. There are less than 4,500 people who are resident on St Helena, so any influx to the island would have an impact.

“This is the kind of place where you know pretty much anyone you pass on the street on a first-name basis. The cultural shock alone would have a big impact.”

Friends of the British Overseas Territories, a campaign group, said the deal showed a “lack of understanding” of the problems on St Helena by the British government.

“Saint Helena is a small island with public services that already face a number of pressures,” said a spokesman.

“The last thing it needs is an undetermined number of illegal migrants being homed there for an unspecified length of time.

“The local government is understandably eager for extra funding, and it’s shameful that the UK Government is using funding as a tool to foist this deal upon them.”

A Foreign Office spokesman told The Telegraph that the deal had been struck after the current government inherited a “deeply troubling situation” of migrants stuck on the Chagos Islands for years, “resulting in mounting legal challenges”.

“Ministers have worked hard to find solutions and contingency plans which protect the integrity of British territorial borders and migrant welfare,” the spokesman said.

“This arrangement will only apply if migrants arrive in the future on Diego Garcia.”