Diego Garcia Military Base and British Indian Ocean Territory Bill

Debate between Lord Beamish and Lord Murray of Blidworth

2nd reading
Tuesday 4th November 2025 Lords Chamber

[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.