Diego Garcia Military Base and British Indian Ocean Territory Bill

Lord Coaker Excerpts

Report stage
Monday 5th January 2026 Lords Chamber

[Lord Morrow (DUP)]

My Lords, I wish to make some comments on Amendment 22 in my name, and I will seek not to transgress my time in relation to this one.

In Committee, the noble Lords, Lord Lilley and Lord Callanan, and the noble Baroness, Lady Goldie, pointed out the difficulty arising from the fact that while the Mauritius treaty makes provision for the leasing of Diego Garcia by the United Kingdom, this does not change the fact that in the event that the Mauritius treaty is ratified, Diego Garcia would come under the sovereignty of Mauritius.

This is problematic for two reasons at least. First, the Republic of Mauritius is a signatory to the Pelindaba treaty, which means that no nuclear weapons can be held in the territory over which it is sovereign. Secondly, Article 7 of the Mauritius treaty expressly states:

“Each Party confirms that none of its existing international obligations or arrangements now in force or effect between it and any third party is in conflict with the provisions of this Agreement, and that nothing in this Agreement shall affect the status of existing international obligations or arrangements except as expressly provided for in this Agreement”.


Can the Minister confirm—I know the noble Baroness, Lady Goldie, has already made reference to this—that the Government have discussed this matter in its entirety with the Government of the United States and that they have confirmation from the US that they have secured their solemn pledge that no nuclear submarines or other nuclear weapons will be able to be taken to Diego Garcia if sovereignty is transferred?

I look forward to hearing what the Minister has to say on that point. But I very gently say that while of course he must not discuss operational matters, this cannot be pushed as an excuse for dodging questions about compliance with international law. Any attempt to deploy that stratagem, to the point of avoiding the demonstration of compliance with international law when non-compliance is feared, would form a deeply troubling precedent.

[The Minister of State, Ministry of Defence (Lord Coaker) (Lab)]

My Lords, it is a pleasure to get up for the first time on Report and address your Lordships on this important group dealing with security matters. I will try to come to some of the points that have been raised.

I will come to the point about the letter that the noble Baroness raised, but I will start with the challenge that she put at the end to explain how the Government are dealing with the position on the treaty from a security point of view. This answers some of the questions that have been asked, not least by the noble Lord, Lord Morrow, and I will not go into some of the operational points that have been made by him and others. However, on the security matters, I can say that if your Lordships look at the expressions of support for the security aspects of this treaty, all our major international allies and partners have supported the security arrangements. That is a fairly significant point for us to make and a fairly important point for the House to recognise.

To answer the noble Baroness, the noble Lord, Lord Morrow, and the noble Earl, Lord Leicester: President Trump expressed support for the Diego Garcia arrangements within the treaty. US Secretary Hegseth said:

“Diego Garcia is a vital military base for the US. The UK’s (very important) deal with Mauritius secures the operational capabilities of the base and key US national security interests in the region. We are confident the base is protected for many years ahead”.


That was not me but the US.

[The Earl of Leicester (Con)]

What is the US paying Britain for the lease? It is pretty clear why the Americans are supporting this: they are not having to shell out £34 billion.

[Lord Coaker (Lab)]

The US pays for the operations at the base and has done for many years. I say to the noble Earl that it is a fairly important policy that the Government have secured this to ensure the security of the base over the coming decades. I will come to AUKUS in a minute, but the noble Earl, the noble Lord, Lord Morrow, and other noble Lords have asked in their amendments how the treaty arrangements protect the security of the base. All I am doing is reading out what our crucial allies are saying about it. I am saying what they are saying about it. They are paying for the operation of the base. We have secured the future of the base, and they are supporting it. Secretary Rubio came out and supported the base as well.

People ask me how we have secured it—this is the challenge the noble Baroness put to me—and how we have ensured that we have secured the future of the base. We have secured it by ensuring that our major allies support it. I can only imagine what the noble Earl would say if I could not read out quotes from the US supporting what we are doing. The Five Eyes have all supported it. Of the AUKUS partners, Australia supports it as well as the US. Canada, Japan, Korea and India have supported it. I think that is an important position for the Government to be in. That is the context within which all the amendments should be considered.

I do not question the desire of noble Lords in their amendments to challenge the Government and to understand how effectively we have done that. All I am arguing before your Lordships is that, in the context of the treaty, the future of the base is secured. That is a fairly important statement for the Government to be able to make. I will come to the Pelindaba treaty when I come to the amendment from the noble Lord, Lord Lilley, and address the specifics that the noble Baroness raised.

Amendment 8 tabled by the noble Lord, Lord Callanan, requests a statement from the Secretary of State on base security. The treaty has robust security provisions to protect the base, including full operational control of Diego Garcia, full UK control over the presence of foreign security forces across the archipelago and an effective veto over any construction or development that risks undermining, prejudicing or otherwise interfering with the long-term, secure and effective operation of the base on Diego Garcia. Claims that Mauritius is an unreliable partner and one that cannot be trusted are unfounded. Mauritius is a member of the Commonwealth and a westward-facing country with shared democratic values. Mauritius ranks among the top African nations in governance, human development and innovation. It is a full democracy, a regional leader in human rights and a trusted partner in upholding the rules-based international order, ranking second out of 54 African countries in the Mo Ibrahim Index of African Governance.

I thank the noble Lord, Lord Lilley, for tabling Amendment 14 and the noble Baroness, Lady Goldie, for supporting him. The noble Baroness asked me—I hope this helps the noble Lord, Lord Lilley, as well; I always try to be helpful, as noble Lords know—to ask my officials to draft a letter between now and Third Reading. Of course I will do that. I cannot guarantee that the content will necessarily be everything that the noble Baroness or the noble Lord want, but asking for a letter is a perfectly reasonable request. That will be done, and I will place a copy of it in the Library so that it is available to all noble Lords to consider as we move towards Third Reading.

Regarding the amendment tabled by the noble Lord, Lord Lilley, he knows—he has been a senior Minister and has a distinguished former Prime Minister sitting next to him—that it is very difficult to answer some of the specific questions that noble Lords have posed about certain capabilities. The noble Baroness, Lady Goldie, recognised that we cannot talk about it. I will say what I can. Amendment 14 tabled by the noble Lord, Lord Lilley, would require guarantees

“that Mauritius will not enforce its duties under the Pelindaba Treaty on the Base”

and that sovereignty would revert to the UK if it did. As I said in Committee, the Governments of the UK and Mauritius are both satisfied that the Diego Garcia treaty is compatible with their existing obligations under applicable international law. The UK will ensure that all operations on Diego Garcia comply with its existing obligations. The UK is not a party to the Pelindaba treaty, although it is a party to Protocols I and II. The treaty and the Bill will allow the base to operate as it always has. It will not reduce our ability to deploy the full range of advanced military capabilities to and from Diego Garcia in any way.