Former residents of the Chagos Islands who were forcibly removed from their homeland more than 40 years ago have lost their legal challenge to return.
Families left the Indian Ocean islands in the 1960s and 70s to make way for a US Air Force base on Diego Garcia, the largest of the group of islands.
An Immigration Order preventing anyone from going back was issued in 1971.
The Supreme Court - UK's highest court - upheld a 2008 House of Lords ruling that the exiles could not return.
Olivier Bancoult, the Chagossian leader who has been fighting in the courts on behalf of the islanders, had argued that decision should be set aside.
In the latest challenge, justices were told it relied heavily on a 2002 feasibility study into resettlement, which concluded that the costs of long-term inhabitation of the outer islands would be prohibitive and life there precarious.
Information about the feasibility study was not disclosed before the decision was made, the islanders said.
But the five justices dismissed the islanders' appeal by a majority of three to two - the same numerical split as the Law Lords in 2008.
Sabrina Jean from Crawley, West Sussex, chairs the Chagos Refugees UK group. Her father was originally from Chagos Island and is one of the 3,000-strong Chagossian community who live in the town, which is near Gatwick Airport.
She told BBC Sussex: "We are disappointed about the result but we will never give up. We will continue our fight to find justice for the Chagossian community. All the people have the right to live on the islands."
At Prime Minister's Questions on Wednesday, Henry Smith, MP for Crawley asked David Cameron if it would be a good legacy to allow the islanders to return.
Mr Cameron said the National Security Council was considering the case and had looked at the alternative options and costs.
"We will be making an announcement in the coming months," he said.
Stefan Donnelly, of the UK Chagos Support Association, said the decision was "disappointing" after decades of "peaceful and powerful" campaigning but "justice is still within reach though".
"It is ministers' responsibility to conclude their long-running policy review on the resettlement of the Chagos Islands," he said.
"Chagossians are our fellow citizens and we need to stand together and demand ministers get started on a fair return programme now."
TV presenter Ben Fogle has supported the campaign.
He said it was "hard to accept the ruling", but added: "The government's own policy review has already concluded that return is feasible, costs are modest and plenty of Chagossians are ready to go.
"So this fight for justice will continue - and grow."
UKIP's Commonwealth spokesman James Carver MEP said he was "dismayed" by the ruling, saying: "This moral injustice continues to be a stain on our history."
The Supreme Court case was the latest in a long legal battle over the right of the islanders to return.
In 2000, High Court judges ruled that Chagossians could return to 65 of the islands, but not to Diego Garcia.
In 2004, the government used the royal prerogative - exercised by ministers in the Queen's name - to effectively nullify the decision.
Then in 2007, the court overturned that order and rejected the government's argument that the royal prerogative was immune from scrutiny.
However, the following year the government won an appeal, with the House of Lords ruling the exiles could not return.
Labour leader Jeremy Corbyn has been a long-standing supporter of their campaign to go back.