PARLIAMENTARY DEBATE
British Indian Ocean Territory: Sovereignty - 2 July 2025 (Commons/Commons Chamber)

(Urgent Question): To ask the Secretary of State for Foreign, Commonwealth and Development Affairs if he will make a statement on the ratification of the UK-Mauritius treaty on the future sovereignty of the British Indian Ocean Territory.

I thank the right hon. Lady for her question. On 22 May, the Diego Garcia treaty was signed and laid before the House. As the Defence Secretary told the House on the day of the signature, this treaty secures the strategically important UK-US military base on the island of Diego Garcia. The Diego Garcia military base is essential to the security of the UK and our key allies, including the United States, and is essential to keeping the British people safe. It is also one of our most significant contributions to the transatlantic defence and security partnership.

The base enables rapid deployment of operations and forces across the middle east, east Africa and south Asia, helping combat some of the most challenging threats, including from terrorism and hostile states, and it has a unique strategic location. The treaty ensures that the UK retains complete operational control of Diego Garcia well into the next century. It has robust security measures that prevent threats from the outer islands of the archipelago, including: a 24 nautical mile buffer zone where nothing can be built or placed without UK consent; a rigorous process to prevent activities on the wider islands; a strict ban on foreign security forces on the outer islands, whether civilian or military; and a binding obligation to ensure the base is never undermined. These robust provisions give the UK an effective veto over any activity that presents a clear and direct threat to the base on Diego Garcia, and they will categorically prevent our adversaries from compromising the base.

The treaty sets out that it can be ratified once both parties have completed their relevant domestic processes, and for the UK this of course includes scrutiny of the treaty by Parliament and making the necessary changes to domestic law. The treaty was laid before the House on the day of signature for scrutiny under the usual process set out in the Constitutional Reform and Governance Act 2010. We welcome the report into the treaty by the International Agreements Committee in the other place, which recognised the importance of ratifying the treaty to secure the base, and the debate on Monday in the other place in which peers rejected a cynical Conservative motion to block ratification.

Nevertheless, before the treaty is ratified, the Government will also bring forward primary legislation, as I have said on many occasions, which will be scrutinised and debated in the usual way, and secondary legislation as necessary. Ahead of ratification, the Government will also make a ministerial statement in both Houses, providing a factual update on Chagossian eligibility for resettlement and on the modalities of the Chagossian trust fund. That will also enable further discussion in a proper manner. The treaty will then enter into force on the first day of the month following the date on which both parties have exchanged letters confirming these processes are complete.

This landmark agreement secures the future of our strategically critical UK-US military base on Diego Garcia. It is, as I said, a crucial contribution to the defence and security partnerships that we hold. As the Defence Secretary told this House, there was no alternative but to act, and in so doing we have protected Britons at home and overseas. [Interruption.] If the Opposition do not recognise that fact, why did they start negotiating in the first place?

Thank you, Mr Speaker for granting this urgent question. With the 21-day CRAG process about to conclude, it is a disgrace that Labour has breached the parliamentary conventions and denied the House a meaningful debate and vote on ratification. The Minister says that we will get a vote on the Bill, but having a vote on the Bill is not the same as voting on a treaty under CRAG.

Earlier this week, the House of Lords had a debate and vote, where the Lib Dems sided with Labour in backing this £30 billion surrender treaty, which is subsidising tax cuts in Mauritius. Why cannot we have a debate and vote in this House? What are Ministers afraid of? Are they afraid that their Back Benchers, now worried about benefit cuts and the impact of unpopular tax rises, will question why so much money is being handed over for a territory that we own and will force them into another embarrassing U-turn? Are they afraid that MPs across the House will do the maths even, and see that the actual amount of money going to Mauritius will be at least £30 billion and not the £3.4 billion accountancy valuation claim that Ministers talk about? Are they afraid that Labour’s barefaced hypocrisy and appalling treatment of the Chagossian community will be exposed?

The Minister once said:

“The people of Chagos must be at the heart of decisions about their future” —[Official Report, 28 October 2015; Vol. 601, c. 192WH.]

but this surrender treaty betrays them. He has betrayed them, leaving any decisions on resettlement and support through the trust fund in the hands of Mauritius.

With a legal case ongoing, will the Minister extend the CRAG process until all legal challenges have concluded? Will the Minister finally admit that Labour made October’s bad deal even weaker by giving up the unilateral right to extend the lease on the base and ditching the clause authorising the UK to exercise sovereign rights? The Prime Minister of Mauritius has said that it has done that, so will the Minister finally admit it? Will the Minister confirm that there are no guarantees that the current levels of marine protections will continue?

There is too much ambiguity; we have not had clarity. There are no guarantees on security or on safeguarding, unanswered questions about notification requirements around the base, and no guarantees that Mauritius will not pursue further lawfare to stop operations at the base if it thinks they contravene international law, including trying to block nuclear weapons, as the Pelindaba treaty now applies to the Chagos islands. The Minister should scrap this treaty or at least have the courage to bring it here for a proper debate, full scrutiny and finally a vote in this House.

I genuinely have to say, as somebody who has respect for and likes the right hon. Lady, that I am disappointed by the tone of those remarks. I do not know who writes this stuff; I do not know whether it is just performative politics, or rhetoric—I don’t know what.

I should point out that I have received and answered over 100 written parliamentary questions from the right hon. Lady. I have answered over 250 questions in total on the deal and the process. We have had no fewer than six urgent questions in this House. We have had two statements from the Government, from the Foreign Secretary and the Defence Secretary. I personally briefed the right hon. Lady and answered many of her questions in my office just a couple of weeks ago, in good faith and in detail. I have been subjected, quite rightly, to robust scrutiny on these issues not only by the Foreign Affairs Committee, but by the International Relations and Defence Committee and the International Agreements Committee in the other House, in great detail.

I do not know whether the right hon. Lady and her team are simply not reading the transcripts or the answers to the questions, but I have repeatedly answered them. She might not like the answers, Mr Speaker, but I have answered these questions. I have set out the position on costs. I have set out the position on the security arrangements. I have set out the position on the vetoes that we have. The fact is that this deal secures this base, and it secures our national security and that of our allies. It is absolutely right that it has had proper scrutiny, and there will be a vote, because there will be a vote on the legislation that we will put before the House in due course.

On a recent visit to Washington with the Foreign Affairs Committee, I was struck by the support expressed by the US Government for the deal to secure the long-term future of the military base on Diego Garcia. Alongside the US, our Five Eyes allies support the deal, NATO supports the deal, and India supports the deal. Does the Minister agree that the Opposition would do well to listen to our closest neighbours and allies instead of trying to play party politics with our national security?

My hon. Friend is absolutely right. National security is the top priority of this Government, and working with our crucial allies, including the United States, is key to that. He is absolutely right to point out the support that was gained for this deal through a full and detailed inter-agency process in the United States, at the highest levels of the Administration, as well as the support from our Five Eyes partners and from India. The fact is that this deal secures the base and secures our capabilities, and it would not have been signed off if it did not do that.

I call the Liberal Democrat spokesperson.

The shambolic process of securing this deal has left many questions for the House, but the glaring omission at the heart of that negotiation has been the failure by successive Governments to properly consult the Chagossian people. For much of their history, Chagossians have been denied consultation on who governs them and their right to self-determination. We Liberal Democrats now fear that in handing over the sovereignty of the islands to Mauritius without properly reflecting the interests of Chagossians, the Government are only reinforcing that legacy.

The right hon. Member for Witham (Priti Patel) criticises the actions of Liberal Democrat peers in the other place, yet only the Liberal Democrats championed the rights of the Chagossian people and secured a commitment from the Government to make statements to both Houses on their approach before ratification. In the light of those shortcomings, it is wrong that the Government have not brought the treaty to this House for scrutiny. Will the Minister reverse that decision today and give parliamentarians the opportunity to assess and vote on the final deal?

I genuinely thank the hon. Gentleman for the generally constructive way in which he and his colleagues have approached the process. He is absolutely right to speak about the Chagossians. Indeed, as I have pointed out many times, the Chagossians’ interest in this matter has been at the heart of our discussions. We have the trust fund; we have the agreement to start visits again. Of course, Mauritius will be able to restart a programme of resettlement. He has heard the remarks made by my noble Friends in the other place, in response to the questions that his honourable colleagues raised. We have been very clear about what we will do in that regard, and I hold to that here today.

I have to challenge the suggestion that the treaty has not received scrutiny. It is receiving scrutiny right now. It has been receiving scrutiny in the Foreign Affairs Committee, it has received scrutiny in the other place, and it has received scrutiny through parliamentary questions. It is receiving scrutiny and it is absolutely right that it does.

The Minister has just set out the scrutiny that this matter has received in various places, but I was really taken by the number of questions that he said he had received from the shadow Foreign Secretary on this subject. Can he tell me how many questions he has received on other matters of global importance?

My hon. Friend asks an important question. Since the treaty was laid, I have had 50 written questions from the right hon. Lady. In comparison, I have had four on Gibraltar, two on Ukraine, and one on Poland. He is right that this matter has received scrutiny.

I am not being funny, but it is amazing that the Minister had those figures to hand.

The hon. Gentleman, for whom I have a huge amount of respect, keeps saying that the Government had no choice but to do this deal. I do not believe that to be true. My successor, Lord Cameron, did not believe that to be true either, which is why neither he nor I signed off an agreement. Will the Minister please explain to the House in detail why he believed that he had no choice, including what body, at what time, and with what jurisdiction?

In the interests of time, I refer the right hon. Member to the detailed evidence that I gave in the House of Lords on this matter the other day, including on the legal circumstances. He knows the risk to the operation of the base in the medium and short term, and he recognises the risk of a binding legal judgment, which we believed to be inevitable. His Government knew that, which is why they started the process. He may not have been able to conclude the deal—I accept that, Mr. Speaker—but the previous Government went through 11 rounds of negotiations because they recognised the importance of doing this deal. They knew that securing the facility was crucial to our national security. We put our national security and securing this base first, and that has met with the approval of the United States and other Five Eyes allies.

I have to admit that I am rather confused, because I am sure that the shadow Foreign Secretary was in the Cabinet when the decision was made to start these negotiations. Too often, we focus on the military aspects of this deal, but can the Minister confirm that it will also end a dangerous, irregular migration route into the UK?

My hon. Friend is absolutely right. This Government took early action—even before the conclusion of the deal—to ensure that that route was closed down by the memorandum of understanding that we reached with St Helena, for which I again thank St Helena. Again, Mr. Speaker, I was rightly scrutinised by this House on that. My hon. Friend is absolutely right on that point, and that is why we have done this deal.

Can the Minister tell the House why he thinks China supports this deal?

I have been very clear on this: the United States, our Five Eyes partners and India support this deal. Mauritius was one of the few countries not to join the belt and road initiative. It is very clear that the deal is in the interests of our security and that of our allies—otherwise, the United States would not have agreed to it in the first place.

My hon. Friend is right. Whether it is in the ambitious agenda for national security and defence set out in the strategic defence review, in the unity and leadership we showed at the NATO summit last week, or in securing our crucial national security bases, including Diego Garcia, this Government are leading from the front when it comes to national security. Quite frankly, the Conservative party is showing some brass neck after hollowing out our armed forces, leaving this deal undone and so many other things. I simply do not understand it, Mr. Speaker.

I simply ask the Minister the same question that I asked when he first came to the House on this matter. In relation to the cost consequences of this deal, he knows that the lion’s share of the interest lies with the military base on Diego Garcia. Therefore, what contribution is the United States making to the very significant costs of compensating the Mauritian people?

The United States makes significant and crucial contributions to the operations from Diego Garcia. They are of a quantum much greater than the cost that we will pay in relation to the base under this deal. The benefit to the United Kingdom, the United States and our allies is priceless, and this Government will not scrimp on our national security.

The cost of this deal is equivalent to a quarter of 1% of our defence budget, and that is in the context of a Government who have made the highest sustained increase in defence spending since the cold war. When the Minister speaks to our international friends and allies, what is their message about the work that we are doing to restore confidence in national security and our reputation on the global stage? And what message should the Opposition take from those conversations?

I repeatedly hear a strong vote of confidence in our investment in national security and defence, whether it is from our European partners or from the United States. One just has to look at our leadership at the NATO summit and our ongoing support for Ukraine, which we agree on across the House. My hon. Friend asks about the value and the costs. I have set out the costs on a number of occasions, but, as he says, it is just a fraction of 1% of our annual defence budget. It would pay to run the NHS for just five hours. It also compares favourably with other allies. For example, France pays approximately €85 million a year for its base in Djibouti. Diego Garcia is 15 times larger and the capabilities are priceless.

The Minister rightly says that the base on Diego Garcia is vital for our national security, and we all agree on that. The key issue is what notification has to be given to the Mauritius Government for the base to be used for operational purposes.

My hon. Friend the Minister of State for the Armed Forces has replied to multiple questions on this topic, as have I. Indeed, I answered these questions in the due scrutiny that I received the other day. We do not have to provide notification in advance. The treaty refers to “expeditiously” informing after the event, and that is absolutely the normal course of business. I am clear that the operations and the operational autonomy of this base are secure under this deal.

It is amazing that we are to give up an important security base without it being necessary to do so, that we are to pay billions to a Government that will allow them to make tax cuts while we impose tax burdens on our own country, and that the Minister stands here today at the Dispatch Box and says that he does not have time to explain why it is necessary to do so. Surely the way to ensure that we have proper scrutiny of this deal is to have a proper debate, or is he afraid that his own Back Benchers, once they hear the real story, will find it as difficult to walk through the Lobby for it as they did for the welfare reform Bill yesterday?

I have respect for the right hon. Gentleman, but I totally reject his assertion. There is full support for this deal—and, indeed, full support for it from our allies in the United States and the Five Eyes partners. On the point about alleged tax cuts, at no point in his Budget speech did Prime Minister Ramgoolam say that he was planning to fund income tax reform with the money from this deal. That was very, very clear. Indeed, the rationale for this deal, which I have explained multiple times to the House, is that our national security was at risk and the operations of that base could not function as they once did. That is why the Opposition started the negotiations and why we have concluded them.

After yesterday’s complete chaos, my constituents are bracing themselves for big tax increases in the autumn. How does the Minister think they feel when they see the Mauritian Government crowing about virtually abolishing income tax in Mauritius thanks to the largesse that he is about to pour on them?

I am genuinely surprised by the comments of the right hon. Gentleman. As a former Defence Minister and someone who has served, he will know the importance of this base and the need to secure it, and he will know the risks to our operations that were inherent under the previous Government. That is why his Government started this process and why we have concluded it. It is also why our costs under the deal are broadly comparable with what France pays for its base in Djibouti, even though our base 15 times larger and has immeasurably more capability, as he well knows.

In the Minister’s response, he quoted the answer from the Defence Secretary to my question, saying that he had no choice. But the reason for doing this deal is the worry about being taken to court—so the Government do have a choice, and that is what my constituents and Opposition Members are so upset about. The Government could have a fight in the court and appeal the decision, yet they have chosen not to, and they will not explain why.

Will the Minister set out what the need was for immediacy and why he and his Government will not go to the court for the tribunal he is so worried about to have that fight? If the case were shut down, Opposition Members would understand, and if it was found that we had a legal responsibility to pay, we would do so, but we do not, and we have not had our day in court as a country. That is the travesty of the deal.

I have to correct the hon. Member as we have had days in court on this issue. That is one of the reasons—[Interruption.] There was the non-binding judgment in the International Court of Justice. He also forgets to mention the International Tribunal for the Law of the Sea, the votes in the United Nations and all the other legal processes. The fact is, it is our view—indeed, it was the view of the previous Government—that a legally binding judgment would inevitably follow. Leaving such a key national security asset in that way is not responsible; no, the responsible thing to do is to secure the base with our allies, and that is exactly what we have done.

While China might support this terrible deal, let me tell the Minister that the British people do not support this appalling deal, giving away our strategic security asset and paying tens of billions of our taxpayers’ money in the process. Our taxpayers will be suffering tax rises for that in order that the Mauritians get tax cuts. Since the Government are in the mood for U-turns, why do they not take the hint and U-turn on this terrible Chagos deal?

I will not take any lessons from a party that fawns over Vladimir Putin.

In the Defence Secretary’s statement on 22 May, he stated with regard to potential legal rulings against us that

“The most proximate, and the most potentially serious, is the International Tribunal for the Law of the Sea.”—[Official Report, 22 May 2025; Vol. 767, c. 1291.]

The US, which operates the base, is not even a signatory to UNCLOS. How would ITLOS have ruled a binding legal judgment that we would have recognised? It is notable that ITLOS has not been mentioned since that statement?

I am confused—I have mentioned ITLOS on a number of occasions, including just a moment ago. The long-standing view of the United Kingdom is that the UK would not have a realistic prospect of successfully defending its legal position on sovereignty in such litigation. Even if we chose to ignore binding judgments made against us—we would not do so—their legal effect on third countries and international organisations would give rise to real impacts to the operation of the base and the delivery of its national security functions.

International organisations have already adopted decisions based on Mauritian sovereignty, and others would follow suit following such litigation. That could affect the electromagnetic spectrum, access to the base by air and by sea, and the ability to patrol the maritime area around the base and to support the base’s critical national security functions. Further, the UK would likely face a provisional measures order in a matter of weeks. The position is clear, and we have explained it. The hon. Member’s previous Government knew exactly the same. [Interruption.] However much he shouts and however much he does not like the arguments, they are the facts.

Will the Minister confirm that 40 years ago the most disgusting, cynical injustice was done against the Chagos islanders and that it was their resolute campaigning over decades—often alone, with little friendship or support—that eventually brought the whole case to international law and an opinion from the International Court of Justice, which has brought about the situation we are now in? Instead of obsessing with the twilight of empire, should Opposition parties not be thinking about the injustice done to the Chagos islanders?

Will the Minister confirm that in the arrangements now being made, the Chagos islanders, wherever they are resident, and whatever their opinions are, do have a right of return? Will he give us some idea of what the attitude will be about the right of visit, the right of residence and the right of return to Diego Garcia, where the majority of the Chagos islanders have come from? They are a people who have been badly treated by history and are now being used as pawns by people more interested in defending some strange notion of the twilight of empire than justice for the Chagos islanders.

The primary purpose of the deal was of course to secure the base on Diego Garcia and the national security of the UK and our allies, but the right hon. Member is right to point out the historical situation regarding the Chagossians. We have expressed deep regret for how they were removed from the islands in the 1960s and ’70s; indeed, that is on the face of the treaty. We recognise the importance of the islands to the Chagossians as well as the different views in the community, which he is well acquainted with.

We will be restarting those visits, including to Diego Garcia. The programme of resettlement to islands outside Diego Garcia will be for Mauritius to determine, but we have committed to Members on the Liberal Democrat Benches in the other place that we will provide further statements on how that will work in due course. There is also the trust fund and the support we provide here in the UK. We are listening to the different Chagossian groups and trying to ensure that their interests are at the heart of the treaty deal as we move forward.

The Minister will be aware of a pending judicial review challenge focused on the lack of consultation with the Chagossians. Why was there not full and adequate consultation with the Chagossian people?

I will not comment on ongoing judicial matters, but as I have set out a number of times the negotiations were necessarily between the UK and Mauritius. However, we recognise the importance of the islands to Chagossians, which is why the measures that I just set out have been put in place.

On a point of order, Mr Deputy Speaker. In answer to the hon. Member for St Ives (Andrew George), the Minister seemed to imply—to Opposition Members’ ears anyway—that the United States would be paying, I think he said, a larger quantum of the funding for the deal. I think he was referring to the operational cost of the base. May I ask for confirmation that the United States is not contributing at all to the £30 billion lease under the settlement?

Order. That is not a point of order for the Chair, as the hon. Gentleman will appreciate, but if the Minister wishes to respond I will allow him to do so.

Further to that point of order, Mr Deputy Speaker. Perhaps it was because of the noise and the shouting, but I was clear. The United States contributes to the operations on Diego Garcia, and rightly so. There is establishment of that in relation to the exchange of notes between the UK and the United States. It is not contributing towards the costs of the treaty deal.