Diego Garcia Military Base and British Indian Ocean Territory Bill

Lord Craig of Radley Excerpts

Report stage
Monday 5th January 2026 Lords Chamber

Moved by

[Lord Craig of Radley]

1: Clause 1, page 1, line 7, at end insert
“, subject to subsection (2A).
(2A) Sections 2 to 4 of this Act come into force only when the Secretary of State has sought to negotiate an amendment to Article 11 of the Treaty to ensure that the United Kingdom would cease to make payments to the government of Mauritius in the event that the use of the Base for military purposes became impossible.”Member’s explanatory statement
This amendment seeks to ensure that, before the ratification of the Treaty, His Majesty's Government makes arrangements for the terms of payment should environmental or other issues make the military use of the Base permanently impossible.

[Lord Craig of Radley (CB)]

My Lords, happy new year to everyone. I will speak to Amendments 1 and 38. In an earlier debate on the Bill, I raised the concern that the UK is required, under Article 11 of the treaty, to continue to pay Mauritius even were the military base on Diego Garcia to become unusable. There seems to be no break or conditional clause agreeing any reasons why the UK may cease these payments before the 99-year date is reached.

Article 15 sets out how Mauritius may react should the UK cease payment, but this is a reason why Mauritius may terminate the treaty, not the UK. If the UK were to persist in not honouring its obligation to pay, the treaty would perforce be terminated by Mauritius. For the avoidance of doubt, would that mean that Article 1 of the treaty is still applicable and sovereignty would remain with Mauritius? Can the Minister confirm the Government’s view on this? I have forewarned her of this question.

In Committee on 18 November, the Minister said in response to my question about the base no longer being usable:

“I will reflect on this and try to come back to him with a more thorough response, because I can see that he … wants to know that the Government have given this the proper consideration that he would expect. I undertake to do that”.—[Official Report, 18/11/25; col. 772.]

If she has written with this further information, I have not yet received it. Fundamentally, does she feel that the environmental risks and the risks of other possible events, such as a major destructive attack on the base or even a decision by the United States that it has no further use for it, are sufficiently remote and unlikely for the UK to be able to accept—or have a possibly messy and even dishonourable termination, where considerable sums of taxpayers’ money may be involved?

As this is Report, I do not intend to do more than point this out without detail, but experience tells us that much can and does change over time. In well under the past 100 years, foes have become friends and friends, potential and real, have become foes. Weapon technology may well change and has frequently done so, as has how operations are mounted and security maintained. America could decide that it has no need for the base for operational reasons or even cease to act as a world police force and revert to isolationism. Is there any legally binding agreement between the UK and the United States that it will continue its use of the base or have need of its use for the 99-year duration of the treaty?

I do not wish to suggest any lack of importance of the base to national and international security at the present time. There is also the putative threat of the sea rising this century due to global warming, flooding the base. My Amendment 1 suggests one feasible way to correct this apparent lack of foresight. I shall listen with close interest to the Minister’s response, but unless the Government can reassure the House that the issue of non-usability of the base has been fully considered and a reasonable solution adopted, I may seek the views of the House. I beg to move.

[Lord Houghton of Richmond (CB)]

My Lords, I rise to speak in support of Amendment 1, to which I attach my name, and to reinforce the arguments made by my noble and gallant friend Lord Craig of Radley. This amendment is not moved by any wider purpose than common sense, and we trust that the Government will respond accordingly.

Currently, the Bill makes no provision for the circumstances under which the requirement to pay an annual fee for the use of the Diego Garcia base is revisited in the event of the base becoming unusable for military purposes. My noble and gallant friend has already mentioned the potential risks to the utility of the base arising from an extreme environmental event, the future potential for a policy change by the United States and the potential for the technical obsolescence of the base to come about. I argue that concerns regarding potential legal initiatives to constrain the use of the base, particularly partial constraints deriving from nuclear exclusion agreements or the question of Mauritius as the sovereign power having to honour obligations for the authorisation of offensive operations from the base, should be added to that list of concerns.

I fear that the greatest future concern should perhaps be the full or partial destruction of the base through military action by a hostile state. This might seem a surprising concern given the extremely remote nature of this base, but I have been to it. I argue quite strongly that the strategic importance of the base, its entirely militaristic purpose and its extreme remoteness from civilian life all combine to make it a highly vulnerable and attractive target.

The principal tenets for the use of force in warfare are distinction, military necessity, humanity and proportionality. Pause for a moment to imagine the early stages of a global conflict, when a desire for escalation dominance prompts a hostile nation to destroy a western strategic asset as a proportionate response, with no risk of collateral damage to a civilian population, attracting relatively minor moral opprobrium but resulting in huge military benefit. I cannot think of an obviously better or more considered target than Diego Garcia.

Many in the Chamber may think my concerns are drawn from the world of fantasy or nightmare, but do the last 72 hours not give serious cause for concern regarding our ability to predict with certainty the next two years of geopolitics, let alone the next 100? This treaty needs to cater far better for what the future might hold.

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[The Minister of State, Foreign, Commonwealth and Development Office (Baroness Chapman of Darlington) (Lab)]

My Lords, I apologise to the noble and gallant Lord, Lord Craig of Radley, for not writing to him, but I hope that I can answer his concerns this afternoon.

Amendments 1 and 38, tabled by the noble and gallant Lord, relate to the termination of the treaty based on environmental degradation of Diego Garcia island. As I am sure that he will appreciate, given the importance of the base to both UK and US national security, we and the US are working hard to ensure that the base is protected from environmental damage. We have a programme to address coastal erosion and, while we cannot predict future erosion, specific studies have concluded that the overall land area of parts of the island that are not shaped by military construction decreased by less than a single percentage point over the last 50 years. However, I know that this is not really his point. He is using climate change and rising sea levels, but equally a significant pollution event, a meteor strike or something else could happen, so have the Government considered what they would do in an unpredicted and unpredictable situation that may arise and render the base unusable? That is the kernel of what he is getting at.

For obvious reasons, we do not want to get into a debate about other future hypothetical scenarios, whether they relate to the base becoming unusable or its no longer being needed. It is difficult to see that happening. The US, which has invested heavily in Diego Garcia, agrees that opening up the possibility of the agreement with Mauritius being terminated early is not helpful. However, I take the noble and gallant Lord’s point that, when dealing with a treaty over such a long period, we must at least be aware of the possibility that things can change. That is why we have included in the treaty the joint commission as a mechanism for agreeing between the UK, the US and Mauritius any developments relating to the base that we wish to raise. Should any of the hypothetical scenarios that I have referred to transpire, these are the sorts of issues that could be discussed in the joint commission, with decisions taken based on all the circumstances at the time. We have also included provision in the treaty for the matter to be raised up to prime ministerial level if necessary.

Using these mechanisms the UK and Mauritius would, in close consultation with the United States, agree a way forward. Ultimately, there is provision in the treaty for it to be terminated on two grounds, both of which depend on action by the UK. One is our failure to make payments. As noble Lords know, the UK abides by its international obligations, but in any particular case the Government of the day would need to consider their options in light of all the circumstances, looking at the terms of the treaty as well as wider international law. It is this wider international law, which we have not discussed previously, that I encourage the noble and gallant Lord to consider. He may wish to bear in mind that the international law of treaties permits the termination of a treaty when it becomes impossible for the treaty to be performed as a result of

“the permanent disappearance or destruction of an object indispensable for the execution of the treaty”.

That is wider international law; that is not something that is held within this treaty itself. That is helpful and I hope it reassures him about his concerns.

I hope that the noble and gallant Lord can see that we are taking steps that are necessary to prevent the base becoming unusable and that, however hard hypothetical situations might be for us to imagine today, there are processes in place established by the treaty to resolve them. Using these processes, based on the circumstances of the time, no doubt any future UK Government would do what was in the best interests of the UK.

In the same vein, Amendment 6 in the name of the noble Lord, Lord Callanan, discusses the ability to extend the agreement at the end of its initial 99 years. I assure him that there is already provision for the treaty to be extended by 40 years and beyond with the agreement of both parties. Even if agreement is not reached, the UK has the right of first refusal during that first 40 years after the initial period expires, meaning that no other country can use Diego Garcia without the UK being offered use first. I cannot accept his amendment as it seeks to change a carefully negotiated aspect of the treaty.

Similarly, I cannot accept Amendment 40, also tabled by the noble Lord, Lord Callanan, which calls on the Secretary of State to publish a statement of the Government’s understanding of the legal status of the Chagos Archipelago should the agreement be terminated. The noble Lord is aware that the UK honours its international obligations and is committed to the treaty. The grounds for terminating the treaty are incredibly limited, as I have said, and entirely depend on the UK’s actions.

I thought it might be helpful to the noble and gallant Lord, Lord Craig, in particular, to outline a little more detail about from the law of treaties, which I am relying on in my attempts to persuade him this afternoon. Article 61 of the Vienna Convention on the Law of Treaties, which the UK and Mauritius are both parties to, provides that:

“A party may invoke the impossibility of performing a treaty as a ground for terminating or withdrawing from it if the impossibility results from the permanent disappearance or destruction of an object indispensable for the execution of the treaty. If the impossibility is temporary, it may be invoked only as a ground for suspending the operation of the treaty.


Impossibility of performance may not be invoked by a party as a ground for terminating, withdrawing from or suspending the operation of a treaty if the impossibility is the result of a breach by that party either of an obligation under the treaty or of any other international obligation owed to any other party to the treaty”.


That covers the situation that he refers to—sea level rise—but would also cover many of the other situations that, at this stage, we are able to envisage occurring in the future.

I hope that noble Lords feel able to not press their amendments.

[Lord Craig of Radley (CB)]

My Lords, I thank the noble Baroness very much for the way in which she has attempted to deal with my and our concerns. She has certainly pointed to an alternative way, but I still feel that this is something which should and could be sorted out before we get into formal ratification, and therefore I would like to test the opinion of the House.

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[Baroness Foster of Aghadrumsee (Non-Afl)]

My Lords, my Amendment 32 would require a referendum of the Chagossian people, which we have heard about already, before any transfer of sovereignty of the British Indian Ocean Territory could take place. I thank those noble Lords who have added their names to the amendment. I also thank the noble Lord, Lord De Mauley, for bringing us the results from his committee; they have been very instructive to this debate. At its heart, the amendment is very simple. It asks whether a people who were shamefully removed by force from their homeland and who have been denied a voice that the rest of us enjoy should be finally allowed to speak for themselves. I believe the answer to that question is yes, absolutely.

Of course, the Chagossian community did not leave their islands by choice. They were removed by the British state and scattered across the world. Since that moment, decisions about their future, and about a homeland they were forbidden to return to, have been taken over their heads, in rooms to which they were not invited. If there was ever a community entitled to the clearest expression of self-determination, it is this one.

The Minister has argued that a referendum could not alter the terms of the treaty, but that is to misunderstand the purpose of this amendment, or indeed any other amendment which calls for the right of self-determination for the Chagossian community. The issue before us is not whether a referendum rewrites international law but whether Parliament is prepared to authorise the transfer of sovereignty without the consent of the people most directly affected by it. This House has both the historic right and the responsibility to insist that consent comes first.

We have already heard that the UN Committee on the Elimination of Racial Discrimination published its opinion on 8 December. That is something new in the international sphere that we hear so much referred to in this House. It gives its opinion on the process of this treaty and some of its contents, especially in relation to the explicit prevention of the return of the Chagossian people to their ancestral lands in Diego Garcia. In relation to the process which the Government have engaged in, the committee said that the lack of meaningful participation of the Chagossian people is

“affecting their rights and lands, restricting the exercise of their right to self-determination”.

The UN committee clearly believes, despite all that we were told in Committee, that Chagossians have a right of self-determination. I would be very much obliged to hear from the Minister on this specific point when she responds.

I also worry greatly that to proceed without consent from the Chagossian people would establish a deeply troubling precedent—one that I know is already feared by other populations across our cherished overseas territories. If sovereignty of one overseas territory can be transferred without the freely expressed will of its people, then no territory can be entirely reassured. Self-determination cannot be conditional on convenience or on the balance of diplomatic pressure exerted on the UK by a coalition of our adversaries, either through an international court issuing a non-binding advisory opinion or by other means.

In all other parts of our British Overseas Territories, there is a simple principle that is acknowledged by everyone: people get to decide their own future. But the Chagossians are told that this principle does not apply to them because they are not a permanent population. That argument cannot possibly stand because it was our Government who made them not a permanent population; the UK Government ensured that they could not be. To deny them self-determination on that basis is to compound a historic injustice with a present one.

Of course, the Government will be aware that there is now a Chagossian Government in exile. Denied a voice yet again by a Government who trumpet their respect for international law, the Chagossians have now elected their own leader here in the United Kingdom—a Government in exile, if you will. Surely our Government must now acknowledge that they have got it wrong in not seeking the views of Chagossians before handing away their homeland to Mauritius.

What is striking is that the Chagossian community are united in a call for a referendum. The Minister will refer to a broad range of views on sovereignty within the Chagossian community, and that is absolutely true, but the Chagossian community has consistently referred to the right to self-determination, whether they live in the UK, the Maldives or the Seychelles. The Chagos Refugees Group, which seems to be the only group that the UK Government engage with, has only ever called for self-determination. Similarly, the UK Chagossian groups, including Chagossian Voices, BIOT Citizens and others, have echoed that call. Across generations and across the diaspora, they are asking for the same thing: not special treatment but equal treatment; not a veto over foreign policy but a voice for their own destiny.

Taking that wide range of views into account—a point repeated frequently by the Minister in this place, and in the other place—it is clear that this amendment does not dictate the outcome of a referendum. It does not presume what the Chagossians will decide, as the noble Lord, Lord Hannan, has said. It simply says that they must be asked, and the answer must matter. If we are serious about self-determination and believe that it is a principle, not a slogan, then we cannot exempt the Chagossians from it. I urge the House to support this amendment in a cross-party spirit and affirm that no people, especially one wronged so grievously by the UK Government, should be denied the right to decide its own future.

In closing, I refer to Amendment 33 on “Referendum No. 2” in the name of the noble Lord, Lord Purvis. While, of course, I believe my amendment is better as it is a condition precedent to the treaty being implemented, I will also support his amendment because, as we say in Ulster, half a loaf is better than no bread. Despite that, I hope noble Lords will support Amendment 32.

[Lord Craig of Radley (CB)]

My Lords, I regret that I missed the opportunity to add my name in support of Amendment 32 from the noble Baroness. It is remarkable and significant that there is sufficient interest in the Chagossian community, after so many years since they and their forebears were evicted, to form with due process a Government in exile. I have already exchanged emails with the nominated First Minister, Mr Misley Mandarin.

The Minister was perhaps too optimistically dismissive in Committee when she suggested that there was insufficient Chagossian presence on the atoll to form or justify an independent authority. There is none there; they were evicted in the 1970s. There is also the recent finding of the UN Committee on the Elimination of Racial Discrimination to consider. Have the Government considered whether this might influence the thinking and advisory findings of the international court, which triggered this Government’s search for a long-term arrangement for Diego Garcia as a military base?

I note that the other far neighbour of the Chagos Archipelago, the Maldives, has raised seemingly legitimate human rights concerns about the Government’s methods of rushing these matters through this House. The number of amendments on Report is a reasonable measure of the many concerns held in this House. Though the treaty has been agreed, I urge the Government to proceed at a measured pace to allow these many concerns to be properly and fully considered. Will they reassure the House that there is no set time limit for these national procedures to be considered, as, if they were to be conceded, it might invalidate the treaty as signed on 22 May 2025?

[Baroness Hoey (Non-Afl)]

My Lords, before I speak to my Amendments 33A and 18, I totally support the noble Baroness, Lady Foster, in her Amendment 32 and hope that noble Lords will accept that it is a really sensible way forward. So much has happened even since we started talking about this issue a while ago. We have heard about the committee report. I thank the noble Lord, Lord De Mauley, for a very good report which ends up saying what many of us thought: obviously we cannot say it of every single Chagossian but, overall, they feel that they want to stay part of a British island archipelago. We would not be here if there had been no forced removal originally and the people of the Chagos Islands had been afforded a self-determination referendum back in 1965, as the Ellice Islands were prior to their detachment from the Gilbert Islands.

The report of the UN Committee on the Elimination of Racial Discrimination is new. I do not understand why the Government are pushing this so quickly. Why is it being rushed through? Why are we having Report and Third Reading all in the same week, when there is so much controversy over this issue? It seems very strange.