Diego Garcia Military Base and British Indian Ocean Territory Bill

Baroness Chapman of Darlington Excerpts

Report stage
Monday 5th January 2026 Lords Chamber

[Lord Hannay of Chiswick (CB)]

My Lords, I wish briefly to speak to Amendment 40 in the name of the noble Lord, Lord Callanan. I am struck by the fact that, in all his interventions so far in these debates—at Second Reading, in Committee and, now, on Report—he has never referred at all to the report of the International Agreements Committee on this treaty. He also seems not to have registered, let alone to respect, the vote that was taken at the end of the debate on 30 June.

The point I am making is that, were the noble Lord to go back to the documents and the evidence that was tabled at the time when the International Agreements Committee’s report was laid before this House, he would find there the testimony of Sir Christopher Greenwood. It is remarkably convincing and answers the question posed by the noble Lord in his Amendment 40; it describes what Sir Christopher thinks would happen in circumstances where Mauritius returned to a route that involved international litigation.

It is all set out there. He is an extremely distinguished British national judge of the International Court of Justice. It has nothing to do with the advisory opinion. It is to do with his views about the situation that would then exist. He believes that Mauritius would not have too much difficulty in convincing any international court to which it took litigation that the Chagos Islands were transferred at the time of Mauritian independence.

[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.

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[Lord Purvis of Tweed (LD)]

I accept the admonishment with regard to the spelling and drafting. I cannot blame the clerks for that; it is my fault. If, in proposed new subsection (5)(b), “participation in the operation in” and “opportunities of working in” Diego Garcia means jobs, I accept that also.

Recognising that the treaty is some distance from being ratified anyway, I strongly believe that other elements need to be in place, in agreement with the Government of Mauritius, before it is ratified. These measures are some of the elements that should be put in place before the treaty is ratified. We will discuss other elements in considering later groups, but between now and ratification, extra measures should be put in place to ensure that the consent of the Chagossian community is given and that their rights are underpinned by statute.

[Baroness Chapman of Darlington (Lab)]

My Lords, as I have stated throughout the Bill’s progress through the House, I would like to acknowledge at the outset the importance of the islands to Chagossians as well as the different views within the Chagossian community on their future. This Government deeply regret the way the Chagossians were removed from the islands. We are committed to building a relationship with the Chagossian community that is built on respect and an acknowledgment of the wrongs of the past.

I also acknowledge the strength of feeling in this House on addressing the range of issues raised by Chagossian communities here in the UK and in other parts of the world. In this context, I thank the IRDC for undertaking its recent review and publishing its report on the views of the Chagossian community regarding the UK-Mauritius agreement on the Chagos archipelago, including Diego Garcia. As the report acknowledges, there is a wide range of diverse views among the Chagossian community, and I thank the noble Lord for introducing the report.

Such diversity of views is vital when considering Amendments 2, 9, 12, 13, 18, 19, 20, 23, 25, 32, 33, 33A and 55, which pertain to engagement and consultation with the Chagossian communities. I agree with those in this House who say that transparency and frankness with the Chagossian community is vital. That is why I have resisted some of the discussions around consultations and referendums. To give the impression that a consultation or referendum can elicit a change to a treaty that has already been negotiated and signed in a state-to-state negotiation is wrong.

The negotiations on the treaty were necessarily state to state, with our priority being to secure the full operation of the base on Diego Garcia. That is what we have done. This deal will protect our national security for generations and ensure that the UK keeps unique and vital capabilities to deal with a range of threats.

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[Baroness Hoey (Non-Afl)]

Before the Minister sits down, could she tell us whether our very distinguished Attorney-General, the noble and learned Lord, Lord Hermer, had given any advice—admittedly, she cannot tell us what advice—to the Government on the report of the UN Committee on the Elimination of Racial Discrimination, which has come out so strongly against what His Majesty’s Government are doing on the Chagos Islands?

[Baroness Chapman of Darlington (Lab)]

Not that I am aware of. I point out that the committee to which the noble Baroness and others have referred is not a legal body of the UN; it does not speak for the UN or for any UN member states. It is important for noble Lords to be aware of that, so that they are not labouring under a misapprehension.

[Lord Bellingham (Con)]

Before the Minister sits down, could I clarify one point? She is aware that the committee was set up under the UN charter to monitor the International Convention on the Elimination of All Forms of Racial Discrimination. All UN members signed up to that and, although it is advisory, it carries a huge amount of influence, as do the other two tribunals, which are also advisory and which the Government have said they need to go along with.

[Baroness Chapman of Darlington (Lab)]

They are very different things. I encourage the noble Lord to investigate this a little further and am happy to work with him on that. The fact is that this particular committee does not speak on behalf of the UN and there are many equivalent committees across the UN that also do not speak on behalf of member states. If noble Lords want to verify that, it is entirely up to them to do so, but that is the situation.

To continue, the Government’s priority remains the protection of the British people, including British Chagossians. As the location of a military base with sensitive capabilities and assets vital to the UK’s national security, it would not be appropriate for Diego Garcia to be included in Mauritius’s programme of resettlement. However, both the UK and the Republic of Mauritius remain committed to facilitating a programme of heritage visits to the Chagos Archipelago, including Diego Garcia. Chagossians will also retain the opportunity to work on Diego Garcia through contracted employment at the base.

In respect of Amendments 9, 16, 24 and 48 concerning the 2 December decision by the Committee on the Elimination of Racial Discrimination, the Government’s position is clear. The CERD is an independent body of experts that—I am repeating myself, but I want to make it absolutely clear for noble Lords—does not speak on behalf of the United Nations or of UN member states. The UK does not agree with the approach that the CERD has taken. The UN Secretary-General and the African Union chairperson have both welcomed the agreement. The treaty protects the base and our national security, which is why it has also been welcomed by the US, our Five Eyes partners and other important partners who appreciate the strategic importance of the base. Mauritius has also firmly and categorically rejected the CERD decision, and the Government therefore reject the tabled amendments.

Amendment 5 on migrants and asylum, from the noble Lord, Lord Callanan, is not necessary and therefore we do not accept it. The treaty already ensures Mauritian responsibility for and jurisdiction over all migrants arriving to the Chagos Archipelago, including Diego Garcia. The treaty closes a potential illegal migration route to the UK. The UK Government are already in the process of agreeing with Mauritius the separate arrangements referenced in paragraph 10 of annex 2 of the treaty to assess and facilitate that exercise of Mauritian jurisdiction. There are ongoing negotiations; I will not provide a running commentary, but both Mauritius and the UK agree that it would be for Mauritius to take responsibility for any migrants, including for any asylum or international protection claims. There is therefore no need for the Government to provide a report on the negotiations through an amendment to the Bill. I hope that answers noble Lords’ queries about that issue at this stage and that the noble Lord will withdraw his amendment.

[Lord Callanan (Con)]

My Lords, I thank all noble Lords who have contributed to the debate. I thank the Minister for her response, but it seems to me that she still has not answered the fundamental question that many of my colleagues and others have posed to her: why are some UN advisory tribunals to be obeyed without question? They should not be questioned and we have to do exactly what they say, but others can apparently be safely ignored when it does not suit the Government’s case. She tells us that Mauritius was against the conclusion, and I bet it was, but apparently—this is what I have read and I hope it is correct—Mauritius is also actually a member of the tribunal that found against the treaty and recommended that it be disposed of.

We have heard some fantastic contributions, but of course we have not heard the opinion of the FCDO mandarinate on the Cross Benches, who are normally so keen to tell us that international tribunals have to be respected without question—but apparently not this one.

Nevertheless, I am proud to speak alongside every noble Lord who has spoken up for the Chagossian people and outlined how they have been so ill-treated and for so long ignored. The Minister has said a number of times that there is a diversity of opinion within the Chagossian community. I am sure she is right, which is why we need a referendum to determine the absolute view of what those opinions are. I pay particular tribute to my noble friend Lord De Mauley and his committee for the sterling job that it has done in attempting, in so brief a period, to provide at least some information on what the Chagossian community think. The fact that so many of them responded so quickly in the period before Christmas underlines the concerns that many of them have about this agreement.

We also share my noble friend Lord Lilley’s concerns about the reparations. It seems reasonable that, once Mauritius has sovereignty over the islands, it would bear the burden of any future claims for reparations. I am also grateful to the Minister for her clarification about the legal position on asylum seekers.

I will not detain the House any further. I reiterate our firm support for Amendment 19 in the name of the noble Lord, Lord Purvis. It might be only half a loaf but we are grateful for that half. Still, we will also seek to be greedy and support the noble Baroness, Lady Foster, on the remainder of the loaf when those Divisions are finally called. I beg leave to withdraw the amendment.

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[Lord Bellingham (Con)]

We can address those concerns by passing at least one of these amendments.

[Baroness Chapman of Darlington (Lab)]

My Lords, Amendments 3, 31A, 42 and 43 from the noble Lord, Lord Callanan, all relate to the marine protected area and the Mauritian intent to establish its own marine protected area. It will be for Mauritius to implement this MPA. However, we welcome the announcement on 3 November by the Mauritian Government of the establishment of the Chagos Archipelago marine protected area, to be known as CAMPA, and particularly their commitment that no commercial fishing will be allowed in any part of the area.

Amendment 31 from the noble Lords, Lord Faulks and Lord Godson, follows a similar vein, seeking to oblige the UK Government to report on the Mauritian MPA. But we have been clear that CAMPA will be for the Mauritian Government to enforce and fund, and the UK will not be providing direct funding to Mauritius to maintain or set up this MPA. Renegotiation of the treaty at this stage is not a practical proposition, as Mauritius has already made this public commitment to the MPA, which covers the protections requested in the noble Lords amendments. We therefore do not think they are necessary. Likewise—

[Lord Deben (Con)]

What the Minister repeats is what the Mauritian Government have promised. I do not in any way attack what they have promised, but they cannot do it. They have not done it anywhere else, so why are we not insisting that we provide the resources for them to do it?

[Baroness Chapman of Darlington (Lab)]

I will come on to that. It is a perfectly legitimate question, although I would urge people not to speak about the Mauritian Government, who have said everything we would all want them to say on these matters. We work with them in a positive light, and we want to work in partnership with them to make sure that the commitments they have made are followed through. The right way for us to do that is in a more positive way. I was about to come on to the question the noble Lord put, but I will gladly give way to the noble Baroness.

[Baroness Cash (Con)]

I am very grateful to the Minister for giving way because the question is related. The Mauritian Government may be saying everything our Government want to hear, but at the moment we have no mechanism whatsoever to enforce it and to ensure that what happens in the future can also be enforced.

[Baroness Chapman of Darlington (Lab)]

The noble Baroness has amplified the point made earlier by the noble Lord; it is an important point, and I will address it. However, at this stage we are going to reject Amendment 28, which seeks to oblige the UK to publish the proposed arrangements on MPA management and security before entry into force of the treaty. The UK and Mauritius are working together to finalise an arrangement on maritime security to ensure that patrolling, which provides enforcement regarding the future MPA, is maintained after entry into force. We will publish relevant MoUs, including on maritime security, once these are finalised, because we accept that it is vital. Everything that David Miliband said—I thank the noble Lord for reminding us of what he said—we stand by.

Amendments 29 and 30, tabled by the noble Lords, Lord Faulks and Lord Godson, seek to ensure that money is set aside in the treaty for the establishment and maintenance of the MPA, and that the Government amend the treaty to allow for non-payment if Mauritius does not protect the marine environment. We agree that the continued protection of the environment is important. As previously set out, the UK is not going to be providing direct funding to Mauritius for this purpose. It is true, however, that the UK-Mauritius Strategic Partnership Framework does provide for technical support and expertise to enable the Mauritian Government to work alongside the environmental partners noble Lords have referred to, including the Zoological Society of London, to make sure that the ongoing protection of the marine environment is secure. This is separate to the treaty.

The noble Baroness asked what we would do if there was a breach. If the UK believes that Mauritius is in breach of its commitments in Article 5, on the environment, it can follow the process set out in Article 14, on settlement of disputes. There is therefore no need to include a further way to settle any disputes over protection of the environment, so we do not accept these amendments.

[Baroness Cash (Con)]

Before the Minister concludes, my understanding is that Article 14 does not provide for any recourse. There is no sanction, there is no provision, and it is not a mechanism referred to by anyone who has addressed this issue today.

[Baroness Chapman of Darlington (Lab)]

Article 14 has been agreed as the way to settle disputes. A failure to deliver on environmental commitments could be something we would want to challenge, and the process by which we would do that is included in Article 14. In treaties, we do not need to have a sanction or punishment; the right thing to do is to try to resolve these things so that the impact can be changed. What we want is to make sure that the marine protected area is sustained and that what is environmentally special about this place is secured. That is something we all agree on, but where we differ is that I believe that the mechanisms in the treaty are sufficient to allow for that. What will make the real difference is the quality of the partnership we are able to develop with Mauritius on the work with ZSL and other partners, so that it is equipped to comply with the commitments it is making.

[Baroness Cash (Con)]

How are the Government addressing the fundamental fact—which has not been addressed by the Minister, I am afraid—that Mauritius does not have the capacity to police these waters in any way? We are simply in ignorance about all of this.

[Baroness Chapman of Darlington (Lab)]

She said it, not me. That is why you can buy technical assistance; it is why technical assistance exists. We have a technical assistance partnership with many countries. It is a much better way, working alongside countries to make sure that environmental improvements happen. That is the approach the Government have taken, and it is in the treaty.

I hope that noble Lords will consider withdrawing and not pressing their amendments.

[Lord Callanan (Con)]

My Lords, the Minister’s remark to the noble Baroness, Lady Cash, was a little uncalled for.

[Baroness Chapman of Darlington (Lab)]

I was joking.

[Lord Callanan (Con)]

The Minister may say that she was joking, but it was not a very good joke.

I thank all noble Lords who have spoken in this debate. In Committee, noble Lords across the Chamber set out their profound concerns about the practical ability of the Mauritian Government to deliver on their commitments. As I said, nobody doubts what they have said and the statements they have made; however, I think we all doubt their ability to enforce this crucial MPA.

I do not need to repeat all the excellent points that have been made by the noble Baroness, Lady Cash, my noble friend Lord Goldsmith and others in their contributions to this debate; they very closely reflect our concerns. Given the critical importance of the ocean around the archipelago for global diversity, we believe that it is necessary to press the Government on this, so that we can have a formal statement of the Government’s expectations of Mauritius under Article 5 of the treaty. We also believe that we need clarity on what steps Ministers will be willing to take to ensure the maintenance of the MPA in perpetuity by the Mauritian Government. I beg leave to withdraw my amendment.

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[Lord Purvis of Tweed (LD)]

My Lords, I wish to speak to Amendment 50, to which the noble Baroness, Lady Noakes, referred; I am grateful for her support.

This treaty is both a diplomatic measure, when it comes to sovereignty, and a financial relationship; it also adds some obligations to a community whose rights have, as we have acknowledged, been diminished. So it is quite unusual. That is why, at Second Reading, I raised concerns around the financial elements of the treaty, the lack of clarity around how much will be allocated to addressing the rights of the Chagossian community, and the lack of transparency. I acknowledge Letter No. 1, which is appended to the treaty and outlines the figures, but I feel that further clarity is required.

I will not repeat the points I have made previously, but Amendment 50 seeks to address the major concerns around the lack of transparency in the planned implementation of the financial elements of the treaty—including through, as the noble Baroness, Lady Noakes, indicated, a five-yearly update to Parliament on both progress and the contemporaneous situation with regard to the finances.

New subsection (4) in Amendment 50 also introduces what I would consider to be a break clause in the financial relationship outlined in the treaty and in letter one. Earlier in our proceedings, the Minister helpfully said that the treaty could be terminated on two grounds only. The second ground was in reference to the Vienna convention, if there are circumstances which mean the treaty is unimplementable, and the first element is the failure to make payments by the UK.

I say this without suggesting that Mauritius will act in bad faith or has entered into the treaty in bad faith, but there are no mechanisms which would allow us to consider whether Mauritius is also operating to fulfil its obligations, beyond those which have been elevated on diplomatic terms to Prime Minister level for dialogue. If that dispute mechanism has been exhausted, we believe that there should be some formal mechanism by which Parliament should then have the ability to say that the agreement on the finances reached under letter one should require supplementary approval. Indeed, the obligation on the Government of the day would be to come back to Parliament to say that the dispute mechanisms have been exhausted and no agreement has been reached, and therefore that this needs to be brought back. The sums of funds are extremely high; the obligations are serious. Therefore, I hope the Government will consider moving on this element.

Amendment 47, in the name of the noble Lord, Lord Callanan, is not at all contradictory to this, and if he tests the opinion of the House, we will support him on that amendment. I am also grateful so far for the indications of support for my amendment.

[Baroness Chapman of Darlington (Lab)]

My Lords, Amendments 7, 39, 47, and 50 all relate to financial transparency and parliamentary oversight of expenditure under the treaty.

Amendments 39 and 47, tabled by the noble Lord, Lord Callanan, seek to require the Government to publish a schedule of payments to Mauritius and a detailed statement of the total cost of the treaty, including the methodology used by the Government Actuary’s Department and the Treasury. These amendments are not necessary, as we published full details of the financial arrangements on the day the treaty was signed, including the finance exchange of letters and the Explanatory Memorandum laid before Parliament.

These documents set out the payment schedule and confirm that the net present value of the treaty is £3.4 billion in today’s money, calculated using the standard Green Book methodology that successive Governments have applied to long-term projects. The average annual payment is £101 million—less than a 0.25% of the defence budget and a fraction of the cost of comparable overseas facilities. This is a sound investment in our national security, and the figures have been confirmed by the Government Actuary’s Department. For these reasons, we reject these amendments.

Amendment 7, which ties commencement of Sections 2 to 4 of the Act to the discharge of duties under Amendment 47, would introduce unnecessary delay in ratification. The Government have already provided the transparency sought by the noble Lord through the published Explanatory Memorandum and accompanying documents, as well as a significant number of Parliamentary Questions and debates in this Chamber and the other place. We therefore do not accept this amendment.

Amendment 50, from the noble Lord, Lord Purvis of Tweed, proposes an ongoing estimates and supply scrutiny process for expenditure under the treaty, including parliamentary approval of future payments and supplementary estimates. The agreement has already undergone scrutiny under the Constitutional Reform and Governance Act 2010, and neither House objected to ratification during the statutory period.

The treaty provides robust mechanisms for dispute resolution under Article 14. It is normal practice for payments under treaties to be made under the prerogative power. While the standard annual estimates process still applies, the introduction of additional parliamentary approval requirements is not necessary and would undermine the certainty and stability that this long-term agreement provides. As I have said on many occasions, the US covers the running costs of the base on Diego Garcia, which are significant, but any expenditure met by this Government will be published in our annual departmental accounts.

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[Lord Lilley (Con)]

My Lords, I will very briefly talk to my Amendments 10 and 15. When any Administration shift from the original arguments which justified their policy to a new set of arguments, you know that they are moving from evidence-based policy to policy-based evidence. That seems to be what is happening here.

When the original Statement was made about this treaty on 22 May, the Defence Minister in the other place said that if we did not have this treaty, within weeks we would face a binding legal judgment which would in due course render the base inoperable. That was implicitly based on the case before the International Court of Justice, but no mention was made that that ruling was purely advisory, not binding. No mention was made that it was based on General Assembly resolutions, which themselves are not binding and had never been ratified by the Security Council, where, in any case, we have a veto. There was no mention that when we signed up to the ICJ, we specifically precluded it from hearing or being bound by anything relating to disputes between the UK and Commonwealth members, and that subsequently, in 2012, the Cameron Government had tightened that by saying it should be not just present Commonwealth members but present or past Commonwealth members, just in case Mauritius should leave the Commonwealth to pursue its case.

When we mentioned these things, the Government did not say, “Oh yes, you’re quite right: we should have mentioned this earlier”. They simply shifted to talking about the possibility of tribunals in other fora, above all the UN Convention on the Law of the Sea—but that convention cannot address sovereignty. In Committee, the Minister mentioned that in a dispute between Mauritius and the Maldives, in which Britain was not represented, the tribunal assumed on the basis of the ICJ treaty that the boundaries of Mauritius should include Chagos and ruled on that basis. But we have the right in any future dispute that involves us to be represented; above all, we have the right to invoke, I think, amendment 238, which precludes military matters. The Diego Garcia base is above all a military matter. So I do not see where any binding legal judgment could come from, which is why I say that this should not come into force until we see that there is a binding ruling from some international body. If it is going to happen within weeks, that is not going to delay the whole matter very much.

The second issue, which is dealt with in my second amendment, is the reference to any ruling—by whichever international body it is—effectively rendering the base inoperable. When we press on that, we are told that it would mean that countries that supply the base and provide facilities for the base would be able to withdraw those facilities, which in some way would render it inoperable. As to what these facilities are, I presume they get food from neighbouring countries in boats—but nothing much has changed. If countries wished effectively to impose an embargo on the Diego Garcia base, with or without an international resolution from the ICJ or any other tribunal, they could do so. If that would render the base inoperable, the base is much weaker than we thought; and, if they cannot do so, surely there is nothing much to worry about on whether there is a legal ruling.

I do not want to go on at length because I know that noble Lords want to get on to the important business of expressing their views in the Lobbies. But the fundamental basis of this whole treaty has shifted, like the Goodwin Sands—and, like sinking sands everywhere, when they shift, they swallow you up. The Government’s rationale for this whole Bill has been swallowed up by their refusal to just wait and see whether some tribunal would come up with some ruling which would, in some very strange way, render the base inoperable. I find that imaginary but, if it is possible, let us suck it and see.

[Baroness Chapman of Darlington (Lab)]

We have been through this quite a few times, which I suppose is why other noble Lords are not jumping to their feet. Why not wait for a binding ruling? We have discussed previously that that would leave us in a disadvantaged position in terms of negotiation, were we to be negotiating with Mauritius following a binding ruling. The point that there can never be a binding ruling because no tribunal exists that could make one rather begs the question of why the previous Government committed themselves to 11 rounds of negotiations to protect themselves from something that could never happen.

Having said all that, the amendments tabled by the noble Lord, Lord Lilley, concern the legal rationale and the risks of the agreement, including, in Amendment 10, waiting for a binding ruling on sovereignty over the archipelago. I must again reject this argument and this amendment, given that waiting for such a thing, with the treaty with Mauritius not ratified, would put us in an incredibly weak position. It would risk the future of the base, the delay would be highly dangerous to UK national security, and we are just not going to do it.

We published our legal rationale for the deal on the day that the treaty was signed. The House has dedicated hours to debating that rationale. It has been the subject of two reports by respected committees in this place. The Government have been consistently clear throughout all this that the legal case was compelling and there was no credible alternative for managing the risk, which is why the previous Government undertook so many rounds of negotiation. We are confident that this agreement secures the base from legal threat, protecting UK national security for generations. I hope the noble Lord does not press his amendments to a vote.

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[Lord Callanan (Con)]

I thank my noble friend Lord Lansley for the amendments in this group. Throughout the passage of the Bill, we have had some interesting debates on the future of the prerogative. The Delegated Powers and Regulatory Reform Committee has made its recommendations on this point, and I understand why my noble friend has therefore tabled his amendment. The Constitution Committee has drawn Clause 5 to the attention of the House but fell short of matching the recommendations made by the DPRRC. We on the Opposition Front Bench have read carefully the Government’s response to the DPRRC’s report, which we believe has some merit. That said, we will not seek to oppose my noble friend should he choose to divide the House on this matter.

[Baroness Chapman of Darlington (Lab)]

My Lords, Amendments 34 to 37 tabled by the noble Lord, Lord Lansley, seek to amend Clause 5 of the Bill. I appreciate that Amendments 34 to 36 would implement the recommendations of the Delegated Powers and Regulatory Reform Committee. The Government have carefully considered the committee’s report on the Bill and responded to it but, on this occasion, we do not accept those recommendations.

I note what the noble Lord said about Third Reading. I am grateful to him for his detailed engagement with these provisions. I want to clarify one point about which noble Lords might not be entirely clear. The effect of the Bill is that there will be two powers. One is the prerogative power to legislate for Diego Garcia only, which is preserved under Clause 3. We seem to have some agreement on that point. The other power is a new statutory power conferred by Clause 5. Orders in Council made under Clause 5 will be statutory instruments. The Bill currently provides that those will be subject to the negative procedure where they amend primary legislation, and otherwise to no procedure. That is not because we argue that they are prerogative orders but because it is appropriate given their subject matter.

So far as the power to amend primary legislation is concerned, we have been clear that the negative procedure is appropriate, given that the changes to be made to legislation will in very large part be technical in nature. The purpose of the power is to ensure that the Government can bring the domestic statute book into conformity with both the purpose and effect of the treaty, making consequential changes as necessary. That works hand in hand with Clause 3, which provides a default position of continuity of the law. The Clause 5 powers will be necessary to make amendments to that law to adapt it to the treaty and the new status of Diego Garcia. This is not just about the law of Diego Garcia; UK legislation which refers to BIOT needs to be brought into line.

Applying the negative procedure here is consistent with the Cyprus Act 1960, which the noble Lord, Lord Lansley, referred to. Section 3 of the Cyprus Act also provides for the law of the UK in relation to Cyprus or the sovereign base areas to continue and for statutory Orders in Council to be made under the negative procedure to make further adaptations as required.

The Hong Kong Act 1985 also provides for the negative procedure for statutory Orders in Council under Schedule 3, amending the law of the UK or of other British possessions.

The Government’s position is that it is appropriate that no procedure applies when the Clause 5 power is used other than to amend primary legislation. The operation of the base on Diego Garcia and the treaty as a whole are in the realm of international relations, defence and security, as the noble Lord said. Given the subject matter, it is appropriate for those instruments to be subject to no parliamentary procedure.

There will, of course, be statutory instruments, which will be registered and published in the usual way. It is not uncommon for Orders in Council which relate to the overseas territories to have no procedure attached to them. I am happy, and I think it would be a good idea, to continue to discuss this with the noble Lord, Lord Lansley, ahead of Third Reading. I would be very happy to do that. I hope he withdraws his amendment.

[Lord Lansley (Con)]

I am grateful for that response, and in order not to delay the House, if I may, I will leave it at that point. I beg leave to withdraw Amendment 34 and to return to this, if necessary, at Third Reading.

--- Later in debate ---

[Baroness Chapman of Darlington (Lab)]

My Lords, Amendments 51 and 54, tabled by the noble Lord, Lord Purvis, concern the establishment of a UK-Mauritius inter-parliamentary committee to oversee the implementation and operation of the treaty. I would love to please the noble Lord—I am happy to continue talking to him—but I am afraid that I will disappoint him this evening.

Amendment 51 seeks to require the Government to engage with Mauritius to create a committee, with equal representation from both parliaments and the purpose of promoting mutual understanding of the provisions of the treaty. The committee would have responsibilities, including monitoring the implementation of the treaty and its impact on Chagossians. Amendment 54 ties the commencement of the Act to the establishment of this committee.

I completely recognise that the intention behind the amendments is to promote dialogue and scrutiny. However, Mauritius’s agreement to it could not be guaranteed, and the treaty itself makes no provision for an inter-parliamentary committee. Indeed, there would seem to be some potential for overlap—perhaps even conflict—between the proposed role of the committee and that of the joint commission under the treaty. Furthermore, introducing this requirement would at least delay, if not prevent, the ratification and implementation of an agreement that is vital for our national security.

There are numerous committees across the two Houses that can—and, I am sure, will—undertake periodic inquiries into the operation of the treaty. This joint committee could overlap with the work of these Select Committees—and that would not be right. We have Select Committees for a purpose, and it is for them to scrutinise the work of departments, so I do not believe that we should try to replicate that.

I know that the noble Lord feels passionately about supporting Chagossians. He has told me that and I commend him on it, but I do not think a joint committee will increase trust among the Chagossian community. As mentioned on earlier groupings, this Government are committed to a relationship with Chagossians built on trust and acknowledgement of the wrongs of the past. There are also elected representatives in the other place who are there to advocate for their constituents, and there are many in this House who also do this.

The agreement has already been subject to extensive scrutiny under the Constitutional Reform and Governance Act 2010, and both Houses have had the opportunity to consider its terms. The treaty also establishes a joint commission under Article 12 to manage its operation, which is the appropriate forum for bilateral engagement. For those reasons, I hope that the noble Lord will withdraw his amendment.

[Lord Purvis of Tweed (LD)]

My Lords, I am grateful to the noble Lord, Lord Callanan, for his indication of support, and to the Minister for her reply. I listened carefully to what she said. Of course, the joint commission on the treaty is executive-to-executive level, and I have consistently sought an opportunity for parliamentary dialogue to continue. It is absolutely right that elected Members of Parliament will represent their constituents and their constituents’ interests; indeed, MPs in the Mauritian parliament will do likewise. My ambition is to find a vehicle by which that can be done in a systematic way, not to contradict or to conflict with parliamentary committees but for there to be a parliamentary voice on behalf of the community where our commitment for their rights should be ongoing and not end once this treaty is ratified.

I am grateful for the Minister saying that she is willing to continue to talk. Equally, I understand that that is language not to give any commitment to anything at Third Reading, but I would like to continue the engagement with the noble Lord and the Minister on this, and indeed with other parliamentary vehicles. Because of the lateness of the hour—we have had a very busy Report stage—and notwithstanding the importance of this issue, I beg leave to withdraw the amendment in my name.