The funding will go specifically towards the next stage of proceedings involving the Mandarin claimants, ahead of a fresh permission hearing scheduled for November.
The case is one of a number of legal actions involving Chagossians which Great British PAC has helped support financially in recent years.
The original claims, R (Pompe) and R (Mandarin) v Secretary of State for Foreign, Commonwealth and Development Affairs, came before the High Court for an oral permission hearing on October 28, 2025. They challenged aspects of the Government’s decision-making surrounding the UK-Mauritius agreement over the Chagos Archipelago, including allegations that Chagossians had not been properly consulted.
Judgment was handed down on March 10 this year, more than four months after the hearing, with Mrs Justice Stacey refusing permission for the claims to proceed to a substantive Judicial Review. The court concluded that the claims were not arguable, including because of the nature of the Government’s treaty-making and foreign affairs powers.
An appeal followed and Great British PAC says the Court of Appeal subsequently ordered a fresh hearing at which the refusal of permission will be reconsidered. The organisation says that hearing is scheduled for November 5.
The hearing will concern whether the claim clears the permission threshold to proceed further, rather than finally determining the substantive arguments.
Under the established test for Judicial Review, permission should be refused unless the court is satisfied there is an arguable ground for review with a realistic prospect of success. The Courts and Tribunals Judiciary has also described permission as requiring an arguable case which merits full investigation at an oral hearing with the parties and relevant evidence.
Great British PAC chief executive Claire Bullivant said the organisation believed the Chagossians should have the opportunity to put their arguments before the court.
She said:
“Judicial Review exists for an enormously important reason. It allows ordinary people to ask an independent court to examine whether those exercising public power have acted lawfully.
“The permission stage is not the full Judicial Review. The legal threshold is whether there is an arguable ground with a realistic prospect of success. We believe the issues raised by these Chagossian claimants deserve to be properly heard and examined by the courts.
“Legal action of this kind is extraordinarily expensive. Great British PAC has already provided substantial financial and practical support to Chagossians across a number of different legal challenges, and today we have committed a further £10,000 specifically towards this next stage of the Mandarin Judicial Review proceedings and the forthcoming hearing.
“This funding is specifically for this stage, with any support for subsequent stages to be considered separately as the case progresses.
“None of this would be possible without our members and incredibly generous donors. They are the people who enable us to provide support such as this, and I cannot thank them enough.
“For the Chagossians involved, this is about something much bigger than a court date. They argue that they should have a voice in deciding the future of their ancestral homeland. They want self-determination, they want the opportunity to return to their islands as British citizens, and they oppose the transfer of their homeland to Mauritius.
“After everything this community has endured, their arguments deserve to be heard. We stood with them when this case began, we stand with them now, and we will be there on November 5.”
The November proceedings are separate from another Judicial Review the Great British PAC is also supporting concerning Chagossians who travelled to the outer Chagos Islands earlier this year and challenged attempts to remove them. In that case, the Supreme Court of the British Indian Ocean Territory granted interim protection before subsequently considering the substantive challenge.
The November case instead concerns the earlier challenge to UK Government decision-making over the islands and the alleged failure properly to consult Chagossians about decisions affecting their homeland. Keystone Law lists R (Mandarin) v Secretary of State for FCDO among partner James Tumbridge’s cases and describes it as a Judicial Review seeking an order for consultation of the Chagossian people on the future of the Chagos Archipelago.