Diego Garcia Military Base and British Indian Ocean Territory Bill

Lord Beamish Excerpts

Tuesday 4th November 2025 Lords Chamber

[Lord Beamish (Lab)]

My Lords, as a former Defence Minister and current chair of the ISC, I recognise the vital importance of the base on Diego Garcia. It is significant because of its strategic location. It has been vital in combating some of the most serious threats against us and our allies, including from terrorism and hostile states. It has a unique capability of collecting data, which has been used to counter terrorism both abroad and at home. It has made our security, not only ours but that of our allies, greater. It is also a strategically vital logistics hub and protects some strategic shipping lanes. On national security, we usually have consensus across the House, both here and in the other place. Therefore, I am saddened and disappointed that the Official Opposition are using this as a political football on such a vital interest, not just to us but to our allies.

There have been four main issues put forward against the Bill. One is the legal issue around sovereignty; the second is cost; the third is the threat from China; and the fourth is the way in which the Chagossian people have been treated. In opening, my noble friend Lady Chapman outlined the issues around the legal uncertainty surrounding the Diego Garcia base. The excellent report of the International Agreements Committee— I congratulate Members who were involved in it—covers those in good detail but, like all legal questions, there are different opinions. Clearly, the committee took evidence from different opinions in its work and Professor Richard Ekins KC was of the opinion that the ICJ opinion was not legally binding.

As has already been said by the noble Lord, Lord Hannay, Sir Christopher Greenwood said that he could envisage at least two possible routes to make that agreement binding. Clearly, there is a division; there is uncertainty, and that is what the Bill is about, as was said by the Minister in opening the debate, and that is why the last Government entered into negotiations on this.

On the issue around sovereignty, what I find difficult is this. James Cleverly, the Foreign Secretary at the time, said on 3 November, as mentioned by the noble Lord, Lord Purvis, that negotiations would begin

“on the exercise of sovereignty over the British Indian Ocean Territory”

and that it was the Government’s

“intention to secure an agreement on the basis of international law”.—[Official Report, Commons, 3/11/22; col. 27WS.]

The then Government were clear about discussing sovereignty, as the noble Lord, Lord Purvis, said. The rhetoric from the noble Lord, Lord Callanan, is that this is the sovereignty surrender Bill; I challenge the Conservative party to say what has changed in that time, when it was quite clear that the last Government were going to discuss the sovereignty of the Chagos Islands.

The noble Lords, Lord Lilley and Lord Blencathra, said that it was all those nasty people at the Foreign Office who have basically bamboozled Ministers of both Governments, but I agree with the noble Lord, Lord Hannay, that the Conservatives would have come to a similar conclusion: if they had been returned to office, this Bill would have been put forward.

Secondly, on the issue around costs, the noble Lord, Lord Callanan, did the usual trick of adding up all this money to get to £35 billion to give the impression that this money will be paid out tomorrow, when it will be over 100 years. This investment underpins the already huge investment that not only we have put into the Diego Garcia base but, more importantly, the Americans, and will continue to do for years to come. The committee report mentioned Djibouti, as did the noble Lord, Lord De Mauley, and possible issues around size, but this is not an unusual arrangement. However, the joint agreement gives certainty to ourselves and our American allies to invest in the future of that vital capability.

Thirdly, on China, there is a lot of hyperbole spoken on this issue—and not just on this Bill. A lot of ill- informed comment is often portrayed as fact. I urge noble Lords to look at our ISC report of 2023 on China. Yes, China is a threat. Is it a threat to Diego Garcia now? Yes, it is. Will it be in the future? Yes, it will be. But the Bill does nothing to make that more likely. On the issue of China, who is Mauritius’s main interlocutor? It is India. Our Five Eyes partners have all agreed this and think it is a good way forward. It has been suggested that Mauritius will have a veto over military operations; no, it will not, if we look at the Bill—it will have the same rights as the Republic of Cyprus in terms of the sovereign base areas. If military action takes place, people will be informed afterwards. That is not giving it a veto. The idea that China will somehow get close to our very valuable assets there is not the case, because for the first time the outer islands, which are vulnerable, will be secured; that is something we should welcome. It also underpins the strategy of working with our Pacific partners to ensure that we face down China in that part of the world.

Fourthly, on the Chagossian people, I think everyone agrees that the way they have been treated over decades has been completely shameful. This agreement makes a movement forward—as my noble friend said, the funding coming forward allows some limited resettlement —but I urge those Chagossians listening not to be fooled by the Conservative Front Bench. I spent 23 years in the House of Commons, and the only person who consistently raised this issue was the Member for Islington North, Jeremy Corbyn. I never heard a single Member on the Conservative Benches, so it is clearly political opportunism to say now that, somehow, they care about the Chagossian people; they do not at all. I would be very wary about that being put forward.

This is an important Bill. The agreement has the support of our Five Eyes partners and of regional players. Please, if we are talking about national security, this is too vitally important to be kicked around, as it is being, as a political football. We need this Bill. It gives a secure future for our continued occupation of Diego Garcia and, more importantly, the facilities that it brings to keep us all safe.

--- Later in debate ---

[Lord Murray of Blidworth (Con)]

My Lords, to pick up on a theme identified by the noble Lord, Lord Browne of Ladyton, and as identified by my honourable friend Tom Tugendhat on 9 September, when he noted in his speech at Second Reading of this Bill in the other place, yes, negotiations were commenced under the last Government. As Ministers, both he and I wrote to the Prime Minister—both Prime Ministers—to complain about the decision to institute those negotiations. We were right: the treaty was not one that should have been considered then, and it is not one that should be considered now; the whole principle was wrong then, and it is wrong now.

Why do I say that? The main rationale for handing over the islands is that an international tribunal—the International Tribunal on the Law of the Sea—may abuse its jurisdiction in treating the ICJ’s advisory opinion as if it had established, as a matter of binding international law, that Mauritius was sovereign over the British Indian Ocean Territory. As I said when the House debated the treaty on 30 June, the risk of an adverse judgment and the real risk to the operation of the UK-US airfield at Diego Garcia are very significantly overplayed by those who favour this treaty. The ICJ had no such power and did not, in fact, reach the conclusion that Chagos should be transferred to Mauritius. Its advisory opinion left open other courses of action on the UK’s part other than surrender of the islands to Mauritius.

Mauritius cannot, as a matter of international law, secure a binding judgment before an international tribunal establishing that it is sovereign over the Chagos Islands, because the United Kingdom is not required to consent to a dispute of this nature being adjudicated by the International Court of Justice. Accordingly, if I might expand on the point made by my noble friend Lord Lilley, the Government explained their position by saying that they anticipated that another tribunal—as I said, specifically the International Tribunal for the Law of the Sea, which, I may add, has no jurisdiction over questions of sovereignty over territory—will presuppose that the ICJ’s 2019 advisory opinion has settled that Mauritius is sovereign, and will thus proceed to exercise its jurisdiction in relation to disputes about the law of the sea on the premise that Mauritius, rather than the United Kingdom, is sovereign. Yet how can this be, since there is not a word about sovereignty over the Chagos Islands in that advisory opinion of the ICJ?

We must be in no doubt that the Government, on their own account, are handing over a priceless strategic asset and trampling over the Chagossian people as they do so, because they want to avoid being on the wrong end of a potential future abuse of adjudication. However, this is a premature and wholly unnecessary surrender that blazes a trail for other abuses of the ICJ’s advisory jurisdiction to be leveraged into future United Kingdom defeats and compromise of our vital interests. We need to resist now, not only for our national security and that of our global allies but also to refute this abuse of law.

Furthermore, the deal is a terrible one, for the reasons ably outlined by my noble friend Lord Blencathra. Some of the examples are that the terms of the treaty provide very little in the way of leverage or protection for the UK. We cannot, for example, withhold payments for a breach of the terms that nominally protect our interests, and there is no machinery to enforce Mauritius’s commitments. Instead, Mauritius will be well placed to take our money and to reach accommodations with other states in relation to the archipelago that are injurious to our interests.

[Lord Beamish (Lab)]

I am following the noble Lord very closely, and I do not disagree with some of the points is making. Could he, however, clarify why it was that James Cleverly on 3 November said that the Government were to

“begin negotiations on the exercise of sovereignty over the British Indian Ocean Territory”?—[Official Report, Commons, 3/11/22; col. 27WS.]

Clearly, the Government then were talking about the sovereignty of the actual islands.

[Lord Murray of Blidworth (Con)]

As I said earlier in my remarks, that was a decision with which I strongly disagreed then, and I strongly disagree now. He was plainly wrong in so saying.

--- Later in debate ---

[Lord Beamish (Lab)]

Does my noble friend agree that this agreement also allows the Americans to forward plan for their investment, which, as she quite rightly says, is substantial?

[Baroness Chapman of Darlington (Lab)]

Absolutely. I thought the point made by the former Secretary of State for Defence, my noble friend Lord Browne of Ladyton, added to this very well when he talked about how future investment is jeopardised by the legal uncertainty that we are seeking to resolve.

Some have questioned the use of defence money in particular for this treaty. To be absolutely clear, the cost will be split between the FCDO and the MoD, as is appropriate given the shared interests of both departments in maintaining the future of the base. As set out by the Defence Secretary in his Oral Statement on the treaty in the other place, the costs represent a fraction of a percentage of the total defence budget—less than 0.2%. It is a bit far-fetched to suggest that the annual payments are in any way comparable to the biggest uplift in defence spending that we have seen since the end of the Cold War.

The noble and gallant Lord, Lord Craig of Radley, raised sea level change. I do not know why I am dealing with this in the money section, but this is where I have written it down so we might as well get it on the record. As he said, it is true that sea level change has been less than 1% over the past 50 years, but it would be helpful for us to explore in Committee how a future sea level change, which he quite rightly alerts us to, would be treated by the dispute resolution process. I do not have a clear answer to that tonight but that is what Committee is for: getting to the bottom of exactly those sorts of questions.

I will give the last word to the noble Lord, Lord Kerr. He made the very strong argument—it is not one that I had thought of, but I will definitely use it again—that this House voted in July to ratify the treaty. The Bill facilitates the enactment of this House’s wishes, because we voted in favour of the treaty. The Bill is necessary so that we can complete the ratification with Mauritius and therefore secure the critical military base on Diego Garcia. I thank noble Lords for their contributions and look forward to debating this in Committee.