From BBC News:
The US has also indicated that any return of islanders would compromise its military presence.
According to Jeremy Corbyn, Labour MP for Islington North, who has voiced his support for the cause of the Chagossians in the House of Commons, the islanders were "victims of big-power politics".
He said: "These islanders were inconvenient to the nuclear wishes of the United States. This was an injustice of mammoth proportions.
"It was a racist approach to a group of people who had looked after the islands, preserved the islands, who were just in the way."
Most of the islanders were sent to Mauritius and the Seychelles where they encountered racism and discrimination as well as poverty.
In 2002, the islanders were given the right to British passports.
Diego Garcia is part of the Chagos Archipelago in the British Indian Ocean Territories. The Americans are allowed to base aircraft there. But they have no territorial rights.