Keir Starmer’s deal to hand over the Chagos Islands to Mauritius has been dealt another major blow after a court ruling gave islanders expelled in the 1960s the right to live there.
The landmark ruling is a further blow to the beleaguered prime minister, whose efforts to resolve the future of the Chagos Islands, which houses the crucial US-UK airbase on Diego Garcia, has undone almost six decades of previous legal judgements on the islands.
The deal was already in trouble because of opposition from Donald Trump after a row over whether the US could use the airbase for attacks on Iran, the judgment by Justice James Lewis, the judge for the British Indian Ocean Territory (BIOT) Court, could finish off the deal altogether.
The case was brought after four Chagossians occupied one of the islands earlier this year in a bid to reclaim their homes, and the BIOT governor attempted to have them removed.
In his judgement, Justice Lewis has overturned the 2004 law for the islands brought in by Tony Blair’s government to prevent a return to the islands by Chagossians. He has also reversed previous rulings by the Law Lords on their original removal in the 1960s and 1970s.
He concluded that the government’s previous case that there could not be a return to the islands on national security or defence grounds no longer applies because the proposed deal with Mauritius means that the government now accepts the islands can be populated.
He also stated that the cost to the UK taxpayer of the Mauritius deal, which he estimates to be £51bn – higher than any other previous estimate – means that the argument that it is too costly to enable Chagossians to return has also been invalidated.
Justice Lewis has drawn on the UK’s United Nations obligations to conclude that the islanders have a right of abode on their homeland, which makes it almost impossible to give the islands to Mauritius.
The government has already lodged an appeal against the judgment, which has been granted and will be heard by the BIOT Court of Appeal.
The original decision to negotiate a deal with Mauritius came from a ruling by the International Court of Justice (ICJ), which was not binding on the UK, but stated that the islands belonged to Mauritius.
However, this ruling was based on Mauritius being the former colonial administration centre for the islands. Other parts of the British Empire that had been administered from Mauritius gained independence because they were populated.
James Tumbridge, the lawyer acting for the Chagossians, has told The Independent: “Once a population is established on the islands, it changes the entire legal status and means that they should be looked at as their own entity.”
The return to the islands came in an expedition funded by Reform’s biggest donor, Christopher Harborne and led by former Tory MP and Reform defector Adam Holloway.
But in his ruling, Justice Lewis appears to be critical of Nigel Farage and others from Reform, specifically stating that they do not have the right to go to the islands. Mr Farage had tried to join the four Chagossians last month.
