Diego Garcia Military Base and British Indian Ocean Territory Bill

Debate between Iain Duncan Smith and Luke Evans

2nd reading
Tuesday 9th September 2025 Commons Chamber

[Dr Luke Evans (Hinckley and Bosworth) (Con)]

May I say how much of an honour it is to follow the right hon. Member for Islington North (Jeremy Corbyn)? Although we do not necessarily agree on a lot of policy, I am always struck by the fact that he puts people at the heart of his speeches. That has never been the case more than during his long campaign on this issue, on which he spoke eloquently. He is putting Chagossians right at the heart of any decision making. He deserves a lot of acclaim for that. He is right to call out some of the rhetoric in this debate, because, at the end of the day, those people really matter. I thank him for putting his points on the record.

There are three broad areas that I would like to cover: sovereignty, costs and some of the scariest parts of the Bill. I listened to my right hon. and learned Friend the Member for Kenilworth and Southam (Sir Jeremy Wright), and I must admit that I am not nearly as learned or experienced as him; I bow to his legal analysis. I am a mere doctor, so I look for an evidence base when trying to understand the process. To that end, I thought it would be useful to write to the Foreign, Commonwealth and Development Office, which I duly did. I received a letter on 28 July 2025 from the Minister of State, Foreign, Commonwealth and Development Office, the hon. Member for Cardiff South and Penarth (Stephen Doughty), who I see will kindly respond, and is sat in his place. Much to my surprise and pleasure, a lot of what is in the letter was in the Minister’s speech. This debate allows me to walk through some of the letter and pose the questions that hit me as I looked into this case.

I must admit that when I stepped into this House in 2019, this was not a topic that I knew a huge deal about—I think many Members on both sides would say the same—but it very quickly became a topic that I realised we should look into understanding, especially as it deals with security.

The letter states:

“We had to act now because the base was under threat.”

That implies urgency, but the letter is loose on who was under threat, where and how. There is legal uncertainty but, as we have heard, we do not know which court is involved or why. It goes on to say:

“The courts have already made decisions which undermine our position.”

Courts, plural. We know that the ICJ is involved, but as has been stated, its opinion was non-binding, and there is a carve-out relating to the Commonwealth.

The Minister of State, Ministry of Defence, the hon. Member for Plymouth Sutton and Devonport (Luke Pollard), said, after being pushed to speak on the matter multiple times, that the International Tribunal for the Law of the Sea was the area of concern, but he will know that back in 2015, under annex VII, the tribunal agreed with the UK that sovereignty could not be determined by UNCLOS. This was a marine protection issue. Britons were trying to protect the area, and Mauritius wanted to open it up to farm it, and we were found against, under that treaty, in that court. This raises an important side issue: what protections are there in the Bill for the environment? They seem scant, or just not there.

The letter goes further, stating that

“in 2021…a Special Chamber of the International Tribunal for the Law of the Sea…ruled that Mauritius’ sovereignty was inferred from ICJ”.

So the Government themselves point that out. The letter goes on to say:

“The UK was not party to this case”.

Well, obviously, it would not be, but that means that we have not had our day in court to explain why we do not think that the judgment should apply. Mauritius’ sovereignty was inferred from that non-binding, political judgment.

The letter goes on:

“If Mauritius were to take us to court again, the UK’s longstanding legal view is that we would not have a realistic prospect of successfully defending its legal position on sovereignty in such litigation.”

Well, which court? If this advice is so long-standing, why do we not know about it? How have we got this far, going for year upon year with no agreement, without any urgency? It seems sensible and appropriate to release the advice on this. At the start of that quote, the letter said “If Mauritius”. It states later that it is

“highly likely that further wide-ranging litigation would be brought quickly by Mauritius against the UK.”

What evidence do the Government have to back that up? What is it that they say Mauritius will act so quickly on? We certainly have not seen it, if it was from 2021. The dates 2023 and 2024 have been mentioned, and we are now in 2025. I would be interested to see the Government release the evidence base for their claim about how quickly litigation would come forward, because as they rightly point out, there have been 11 rounds of negotiations, so there has clearly been time to sort things out.

Before someone jumps in and says, “Well, you opened the negotiations”, I would point out that we did that for the Falkland Islands as well. I find it amazing that we have trade unionists who built their whole careers on negotiating suddenly chastising the Conservatives for listening to the other side of a disagreement. That seems bizarre to me, because we want to respect each other and exchange ideas, but not have an agreement. It is rightly pointed out by Conservative Members that the agreement was not there; we did not take it. On the cost of the deal, there is no cost, because we did not have a deal to sign off.

The very next sentence in the letter says:

“This might, for example, include further arbitral proceedings against the UK under Annex VII of the UN Convention on the Law of the Sea. A judgment from such a tribunal would be legally binding on the UK.”

[Sir Iain Duncan Smith]

It is not.

[Dr Evans]

It is. It is true about the legally binding aspect within the area that the tribunal covers, but that does not cover sovereignty, as we learned in 2015 when the tribunal sided with the British Government. Here we have the farcical situation of a House of policy and law shining light on one side and another, but never on the truth. This is where my right hon. and learned Friend the Member for Kenilworth and Southam is exactly right. If the Government were to come forward and say exactly which court, where and why, they might get more sympathy from Opposition, but we have been through an entire five-hour debate and we still do not have answers to those questions.

Another court that is often cited is the International Telecommunication Union covering spectre, radio and radar. Article 48.1 states

“Member States retain their entire freedom with regard to military radio installations,”

and the Government know that. Even the written answer from the Minister—it has been hinted at before—states:

“Individual countries have the sovereign right to manage and use the radio spectrum, within their borders, the way they wish, subject to not causing interference with other countries. This right is recognised in the Radio Regulations. The Radio Regulations are the international framework for the use of spectrum by radiocommunication services, defined and managed by the International Telecommunications Union (ITU). Individual countries, not the ITU, make their own sovereign spectrum assignments in accordance with the Radio Regulations. The ITU has no legal authority over these assignments regardless of the country’s civilian or military classification of spectrum. The ITU cannot challenge the UK’s use of civilian or military spectrum.”

It is clear here—the Government know it in their own answers—that the ITU has no role in sovereignty. It all boils down to where one believes British overseas territories stand.

Now we must talk about the cost, which has been much debated. There have been three figures in the debate: £3.4 billion, £10 billion and £34 billion. The £3.4 billion is the net present value using social time preference rate. The £10 billion is inflation adjusted, and the £34 billion is the nominal value by the Government Actuary’s Department. The question is, why use net present value? I put it earlier in the debate that there is no other precedent in the world for NPV being used in sovereignty matters. The Minister at the time asked whether the Conservatives want to do away with using NPV—of course not.