Diego Garcia Military Base and British Indian Ocean Territory Bill

Debate between Lord Purvis of Tweed and Lord Morrow

Report stage
Monday 5th January 2026 Lords Chamber

[Lord Purvis of Tweed (LD)]

My Lords, I gave very careful consideration to the points raised in these amendments by both noble and gallant Lords. They raise significant issues, which I am very sympathetic to. I am also very keen to hear the Minister’s response, given her commitment in Committee, especially in relation to the consequences of Article 1 of the treaty, as the noble and gallant Lord, Lord Craig of Radley, has indicated.

There are, however, elements of the amendments which I am perhaps not entirely persuaded by. They are the conditions within the bailiwick of the Mauritian Government that could give rise to the circumstances where we would seek to stop payments. They are not covered by this amendment, per se. They would, however, be covered in subsection (4) of the proposed new clause in my Amendment 50, which will be discussed much later during our considerations today and which would create the conditions where, if the Mauritian Government by their actions were putting at risk the consequences of our payments, Parliament would be able to pause the payments.

If there are reasons unspecified by Amendment 1 which are non-defence related, there is the potential for UK funding for resettlement support, the trust fund operations or Chagossian community-specific support to be put at risk, so it is worth while to separate out the defence interests from the other elements of the treaties. As the mechanisms in Amendment 50 are preferable in our view, we would find it difficult to support these amendments.

[Lord Morrow (DUP)]

My Lords, Amendment 26 standing in my name states that:

“Sections 2 to 4 come into force only when the Secretary of State has assessed … the impact of the termination of all rights granted by the Treaty to the United Kingdom with respect to the entire Chagos Archipelago through Article 15 of the Treaty”


and

“the impact of the arrangements in Article 15 on the leverage opportunities at the Secretary of State’s disposal in negotiating with Mauritius after ratification”.

Article 15(1)(a) of the Mauritius treaty states that Mauritius can terminate the Mauritius Treaty in the event of

“a failure by the United Kingdom to make payment as required by Article 11”.

This means that if a payment is more than 22 days late, the entire Mauritius treaty is terminated, subject of course to the fact that sovereignty over the Chagos Islands will be in the hands of Mauritius. In that event, we would lose absolutely everything, and if the United States wanted to keep its Diego Garcia base, it would probably have to do so by force. While the United Kingdom could no doubt seek to achieve this, China, Russia and other countries could protest very loudly and have international law on their side. It would provide an excuse for any other power to try to take Diego Garcia and could lead to a major war.

Of course, the Government can respond by saying that this will not happen if we pay on time—and, no doubt, they will assure that we will pay. While we are protected from this eventuality by dutifully paying up completely and always on time, Article 15(1)(a) places the United Kingdom, and by extension the United States, in a formally intolerable, weak position.

To understand the problems arising from the very weak footing on which the treaty places us when negotiating with Mauritius, we must appreciate the huge concerns about what happens in relation to the Chagos Islands beyond Diego Garcia. Mauritius has a clear incentive, arising from the income stream we have promised, to seek additional income streams for leasing other islands or parts of islands. The Government have sought to make much of the fact that we have a veto on the deployment of security and defence forces beyond Diego Garcia, but the problem is that the real threats do not announce themselves as deployment of security and defence forces and are much more subtle. Something that begins as a non-security and defence deployment, in relation to which we have no veto, can evolve into something very different—an emergent risk, over which the treaty affords us no right of veto but only a right to object. The right to object can be resolved only on a consensual basis within the joint committee between the UK and Mauritius proposed by the Mauritius treaty and could no doubt take a long time if Mauritius wanted it to. It is here that our complete lack of leverage provided by paragraph 1(a) of Article 15 is a particular cause for concern.

Mauritius could generally adopt a very unco-operative approach on the joint committee, knowing that, if it resists one of our concerns and we counter by threatening to withhold payment, subject to satisfactory resolution, that will serve simply to renounce all our remaining rights in relation to the Chagos Islands, giving them completely to Mauritius. Of course, if ever a deployment of non-security and defence personnel from another country becomes an emergent risk, and one wherein those concerned in effect become security and defence personnel, the UK would have a right of veto. However, the difficulty is that, by that stage, they will be established in place, and if they did not want to leave, they could be removed only by force, threatening war and international instability.

If we look at other categories of emergent risk, in relation to which we have powers only to lodge objections on the joint committee, we are further confronted by the way in which the terms of the Mauritius treaty—especially paragraph 1(a) of Article 15—rob us of leverage. These risks would all be avoided if the UK did the right thing and corrected the historic wrong of the forced removal of the Chagossians from their islands and afforded them self-determination. While it is plain that not all would vote to be a separate jurisdiction from Mauritius—in the same way that not everyone on the Ellice Islands voted to become a separate jurisdiction from the Gilbert Islands—polling suggests that a majority would vote to become a resettled, largely self-governing British Overseas Territory, legitimately under British sovereignty. In that event, none of the above difficulties would arise.