Diego Garcia Military Base and British Indian Ocean Territory Bill

Lord Thurlow Excerpts

2nd reading
Tuesday 4th November 2025 Lords Chamber

[Lord Thurlow (CB)]

My Lords, in my comments today I wish to give your Lordships a short break from the tangle of treaties and policies and who did what in diplomatic circles. In my contribution, I shall talk about the protection of the ocean surrounding the Chagos Archipelago. In doing so, I thank the Library and others for their assistance. I was encouraged by the Minister’s opening comments regarding the environment.

By way of background, a marine protection area was established around Chagos following a determined and successful campaign by the British charity Blue Marine and others, which persuaded the then Labour Administration to designate an MPA in the closing weeks of the Brown Administration. They created what was then the largest no-take fishing zone in the world—an extraordinary achievement. Blue Marine, together with other NGOs, seeks to protect and restore ocean health worldwide by securing MPAs like this. It has successfully established protection over some 4.3 million square kilometres of ocean—an outstanding achievement—and the Chagos MPA is a significant part of that success. It works.

For those unfamiliar with MPAs, they are precisely that: the designation protects the marine area from overfishing and destructive fishing techniques, and they work to restore marine habitats and support coastal communities with sustainable fishing practices. These large-scale marine reserves enjoy the critical mass to allow the restoration of vital marine ecosystems. They enjoy international acceptance and, critically, they need policing to enforce that protection.

The present arrangement enables the UK to police the Chagos MPA against illegal fishing activity, but what of future protection? The Chagos agreement that we are discussing today refers to a “separate written instrument” that will outline how the management of the MPA and its policing will be managed. Why the simple matter of managing the Chagos MPA cannot be dealt with in the Bill, I fail to understand. Reference to a separate written instrument sounds like a response from an instalment of “Yes, Minister”—a slow process of obfuscation and delay until following the next election, when it all falls apart. I hope not. Will the Minister please explain more of the detail relating to the separate written instrument in her closing remarks? For many, the lack of clarity about how policing and management will be paid for is a worry.

The agreement that we are discussing refers to an annual payment of £35 million, £40 million or £45 million per annum over 20 years, to be gifted as development capital to Mauritius. How much of that will be allocated to managing the marine protected area? Where is the detail? Are we really committing hundreds of millions of taxpayers’ money over 20 years to an agreement with little detail?

The Bill transfers sovereignty of the islands to Mauritius while retaining control over Diego Garcia for 99 years. This dual authority could complicate the enforcement of the environmental protections. While Mauritius has pledged to maintain the MPA—and yesterday’s news is welcome—economic pressures, such as fishing licences and development deals, could lead to relaxed regulations. Experts warn that even slight deregulation could unravel decades of ecological resilience.

We must protect our oceans, just as we seek to protect the rest of our planet from the climate crisis. We are more familiar with the land-based effects of the crisis: the destruction of the rainforest, the growing red list of endangered species and the melting ice. Above all, there is an interdependence between the health of oceans and survival on land. Protecting the health of these oceans seems to me to enjoy fewer column inches in the media, notwithstanding the remarkable television series narrated by Sir David Attenborough, which has been eye-opening and persuasive.

It is worth pointing out that the Chagos Islands are some 2,000 kilometres away from Mauritius. Its maritime enforcement assets include two small planes, which cannot reach Chagos, and two ocean-going vessels. Can we really expect it to invest the sums of money and resources that are required to administer protection and to maintain and enhance this vital MPA? There must be serious doubts about this and about the effectiveness of our agreement with Mauritius, which includes hands-on involvement in the management of this MPA.

With the current awareness of the climate crisis, I do not think that it is appropriate to leave the details of administering this ocean area to a separate written instrument. The agreement risks leaving Mauritius with an overwhelming conservation burden. It is worth noting that the International Agreements Committee of this House considers it vital that an appropriate portion of the annual grant funding be allocated specifically to supporting the marine protected area.

I look forward to the Minister’s responses to these concerns. I would specifically like an indication of how much of the proposed annual payments will be directed towards policing the Chagos MPA.