Diego Garcia Military Base and British Indian Ocean Territory Bill

Debate between Baroness Chapman of Darlington and Lord Craig of Radley

Report stage
Monday 5th January 2026 Lords Chamber

[The Minister of State, Foreign, Commonwealth and Development Office (Baroness Chapman of Darlington) (Lab)]

My Lords, I apologise to the noble and gallant Lord, Lord Craig of Radley, for not writing to him, but I hope that I can answer his concerns this afternoon.

Amendments 1 and 38, tabled by the noble and gallant Lord, relate to the termination of the treaty based on environmental degradation of Diego Garcia island. As I am sure that he will appreciate, given the importance of the base to both UK and US national security, we and the US are working hard to ensure that the base is protected from environmental damage. We have a programme to address coastal erosion and, while we cannot predict future erosion, specific studies have concluded that the overall land area of parts of the island that are not shaped by military construction decreased by less than a single percentage point over the last 50 years. However, I know that this is not really his point. He is using climate change and rising sea levels, but equally a significant pollution event, a meteor strike or something else could happen, so have the Government considered what they would do in an unpredicted and unpredictable situation that may arise and render the base unusable? That is the kernel of what he is getting at.

For obvious reasons, we do not want to get into a debate about other future hypothetical scenarios, whether they relate to the base becoming unusable or its no longer being needed. It is difficult to see that happening. The US, which has invested heavily in Diego Garcia, agrees that opening up the possibility of the agreement with Mauritius being terminated early is not helpful. However, I take the noble and gallant Lord’s point that, when dealing with a treaty over such a long period, we must at least be aware of the possibility that things can change. That is why we have included in the treaty the joint commission as a mechanism for agreeing between the UK, the US and Mauritius any developments relating to the base that we wish to raise. Should any of the hypothetical scenarios that I have referred to transpire, these are the sorts of issues that could be discussed in the joint commission, with decisions taken based on all the circumstances at the time. We have also included provision in the treaty for the matter to be raised up to prime ministerial level if necessary.

Using these mechanisms the UK and Mauritius would, in close consultation with the United States, agree a way forward. Ultimately, there is provision in the treaty for it to be terminated on two grounds, both of which depend on action by the UK. One is our failure to make payments. As noble Lords know, the UK abides by its international obligations, but in any particular case the Government of the day would need to consider their options in light of all the circumstances, looking at the terms of the treaty as well as wider international law. It is this wider international law, which we have not discussed previously, that I encourage the noble and gallant Lord to consider. He may wish to bear in mind that the international law of treaties permits the termination of a treaty when it becomes impossible for the treaty to be performed as a result of

“the permanent disappearance or destruction of an object indispensable for the execution of the treaty”.

That is wider international law; that is not something that is held within this treaty itself. That is helpful and I hope it reassures him about his concerns.

I hope that the noble and gallant Lord can see that we are taking steps that are necessary to prevent the base becoming unusable and that, however hard hypothetical situations might be for us to imagine today, there are processes in place established by the treaty to resolve them. Using these processes, based on the circumstances of the time, no doubt any future UK Government would do what was in the best interests of the UK.

In the same vein, Amendment 6 in the name of the noble Lord, Lord Callanan, discusses the ability to extend the agreement at the end of its initial 99 years. I assure him that there is already provision for the treaty to be extended by 40 years and beyond with the agreement of both parties. Even if agreement is not reached, the UK has the right of first refusal during that first 40 years after the initial period expires, meaning that no other country can use Diego Garcia without the UK being offered use first. I cannot accept his amendment as it seeks to change a carefully negotiated aspect of the treaty.

Similarly, I cannot accept Amendment 40, also tabled by the noble Lord, Lord Callanan, which calls on the Secretary of State to publish a statement of the Government’s understanding of the legal status of the Chagos Archipelago should the agreement be terminated. The noble Lord is aware that the UK honours its international obligations and is committed to the treaty. The grounds for terminating the treaty are incredibly limited, as I have said, and entirely depend on the UK’s actions.

I thought it might be helpful to the noble and gallant Lord, Lord Craig, in particular, to outline a little more detail about from the law of treaties, which I am relying on in my attempts to persuade him this afternoon. Article 61 of the Vienna Convention on the Law of Treaties, which the UK and Mauritius are both parties to, provides that:

“A party may invoke the impossibility of performing a treaty as a ground for terminating or withdrawing from it if the impossibility results from the permanent disappearance or destruction of an object indispensable for the execution of the treaty. If the impossibility is temporary, it may be invoked only as a ground for suspending the operation of the treaty.


Impossibility of performance may not be invoked by a party as a ground for terminating, withdrawing from or suspending the operation of a treaty if the impossibility is the result of a breach by that party either of an obligation under the treaty or of any other international obligation owed to any other party to the treaty”.


That covers the situation that he refers to—sea level rise—but would also cover many of the other situations that, at this stage, we are able to envisage occurring in the future.

I hope that noble Lords feel able to not press their amendments.

[Lord Craig of Radley (CB)]

My Lords, I thank the noble Baroness very much for the way in which she has attempted to deal with my and our concerns. She has certainly pointed to an alternative way, but I still feel that this is something which should and could be sorted out before we get into formal ratification, and therefore I would like to test the opinion of the House.

Diego Garcia Military Base and British Indian Ocean Territory Bill

Debate between Baroness Chapman of Darlington and Lord Craig of Radley

Committee stage
Tuesday 18th November 2025 Lords Chamber

[Lord Craig of Radley (CB)]

I was stressing the point that the agreement is about the Chagos Archipelago, but we are interested in Diego Garcia. If Diego Garcia is not available, the treaty requires us to continue to pay Mauritius for the 100 years or whatever it is. We would then be paying for something we do not even have, let alone have the use of. It would seem sensible to have some arrangement in the treaty to cope with this. I am surprised there is not one. If not, how will it be handled?

[Baroness Chapman of Darlington (Lab)]

We do not expect to be confronted with this situation in the case of Diego Garcia. I am sure there will be adaptations to mitigate this, as there already have been. In the event that sea levels rise to the extent that they would need to in order to make the base unusable, the entire planet would be facing very real threat. That would confront us in very many locations, including Montserrat, St Helena and Ascension. This would probably be the least of our problems.

Out of respect for the noble and gallant Lord and his genuine concern—it is not an unreasonable question— I will reflect on this and try to come back to him with a more thorough response, because I can see that he cares about this and wants to know that the Government have given this the proper consideration that he would expect. I undertake to do that. Luckily, this is the first day of Committee and we have the opportunity to allow ourselves further conversations on these issues.

[Lord Craig of Radley (CB)]

My concern is that we would have to continue to pay under the present agreement, even though there was not a base available.

[Baroness Chapman of Darlington (Lab)]

I understand fully the nature of the noble and gallant Lord’s concern. He has explained it well and repeatedly, and I have committed to come back to him with a further response. I do not think I can do any more than that tonight.

Ukraine

Debate between Baroness Chapman of Darlington and Lord Craig of Radley

Tuesday 25th February 2025 Lords Chamber

[Lord Craig of Radley (CB)]

My Lords, the sum of £3 billion per annum has been mentioned as our contribution to Ukraine, and that indeed is very commendable. I wonder whether it could be increased or whether it is limited in two ways: by the ability to produce new equipment and by the amount by which we have to withdraw from our own front line and munition stocks of our capability in order to support Ukraine.

[Baroness Chapman of Darlington (Lab)]

Part of the defence review will examine exactly that question. What has become clear as this conflict has progressed is that part of the battle is about defence production and capability, so our decisions on spending today will enable us to support Ukraine more securely into the future.

Chagos Islands

Debate between Baroness Chapman of Darlington and Lord Craig of Radley

Thursday 23rd January 2025 Lords Chamber

[Baroness Chapman of Darlington (Lab)]

They are not just mischievous; they are opportunistic, wrong, misleading and undermine the confidence of the Falkland Islanders. Our commitment to the Falklands is non-negotiable, and our commitment to self-determination remains as strong as it has ever been.

[Lord Craig of Radley (CB)]

Will the Minister confirm that, whatever solution is adopted, there will be payments to the Government of Mauritius? If so, will the United States make a contribution? Will she confirm that the Ministry of Defence will not make a contribution?

[Baroness Chapman of Darlington (Lab)]

The noble and gallant Lord invites me to go further than my briefing allows. We do not comment on the payments made for military bases—we never have done and I do not think we will do that any time soon.