Diego Garcia Military Base and British Indian Ocean Territory Bill

Debate between Lord Callanan and Baroness Goldie

Committee stage
Tuesday 25th November 2025 Lords Chamber

[Lord Callanan (Con)]

My Lords, the amendments in this group speak to perhaps one of the most concerning parts of the treaty—although the previous bit was also concerning: namely, the risk that this agreement will undermine our security. Given the large number of amendments in this group, I will speak only to those in my name. I know that my noble friend Lady Goldie will speak to her amendments as well, and I will certainly not seek to pre-empt her arguments in my remarks, as my noble friend is much more of an expert on defence matters than I will ever be.

My Amendment 18 is a commencement block that would prevent the main clauses of the Bill coming into effect until the Government have laid a report on securing a guarantee that all non-UK and non-US civilian personnel stationed on the archipelago will benefit from the provisions of Annex 1. Annex 1 protects the UK’s unrestricted access to Diego Garcia’s sea and airspace. The treaty makes reference to some civilian activity, but we are seeking an assurance from the Government that that part of the treaty in its entirety applies to civilians stationed on Diego Garcia. I hope the Minister will be able to give us that assurance.

Amendment 67 speaks to one of the most fundamental questions, which has already been the subject of much debate. The treaty is clear that the UK must inform Mauritius of any armed attack on a third state directly emanating from the base on Diego Garcia, using the magnificent word, “expeditiously”. The dictionary definition of expeditiously is “quickly and efficiently” and “with speed”. Many have rightly asked what expeditiously means in practice. My Amendment 67 clarifies that the UK Government must not inform Mauritius of any relevant armed attacks until the attack has ended. Providing prior notification to Mauritius, or indeed any third state not directly involved in the attack, could risk the safety of British and American servicemen who are engaged in the relevant operation. Could the Minister confirm that nothing in the treaty requires the UK Government to give forewarning of any attack emanating from the military base? If that is the case then I am sure they can accept the amendment.

Additionally, my amendment seeks a requirement not to notify Mauritius if notification would endanger the security of the base. Can the Minister confirm that nothing in the treaty would prevent the Government withholding notification if notifying Mauritius would endanger the base? My noble friend Lady Goldie will be going into additional details on these important issues.

Amendment 69 in my name seeks to make a point about the location of specific equipment and installations on the base. It is essential that the security of the base is maintained. It would not be acceptable if the UK Government were to endanger the security of equipment at the military base by notifying Mauritius. In replying to the debate, can the Minister please address those concerns? It is essential that the UK Government have the right to refuse notification when doing so would endanger the base itself or our personnel.

[Baroness Goldie (Con)]

My Lords, I associate myself with the remarks of my noble friend Lord Callanan on the amendments to which he spoke. I shall be dealing with the word “expeditiously” and I will try to ensure that that characterises my contribution, and perhaps influences this debate.

I wish to speak to my Amendments 83, 85, 86 and 87. At Second Reading, I raised the issue of the mismatch between the Bill and the treaty that it implements. My main concern in this whole affair is our defence and security and the implications of this Bill on that. I identified a range of areas where greater clarity is required. Before I continue, I should say that I have received a letter from the Ministers, for which I thank them. That sought to clarify some of the questions that I asked at Second Reading. The letter brings a degree of clarification, but in other respects it leaves me with questions. I shall address these as I explain my amendments.

Amendment 83 is simply a technical drafting amendment to accommodate my remaining amendments in this group. It specifies that the commencement of the treaty cannot occur until the conditions outlined in my amendments have been satisfied.

Amendment 85 relates to the specific notification requirements under Annex 1 1(b)(viii) of the treaty. My amendment would require that Clauses 2 to 4 do not come into force until the Secretary of State has published a statement establishing that the notification in Annex 1 1(b)(viii) of the treaty does not require the consent of Mauritius in response. The provision in Annex 1 to which this refers says that:

“In accordance with this Agreement and with reference to Article 2(5) and Annex 2, in respect of Diego Garcia, Mauritius agrees the United Kingdom shall have … unrestricted access, basing and overflight … for non-United Kingdom and non-United States of America aircraft and vessels, upon notification to Mauritius”.


The amendment seeks to enable the Secretary of State to make explicit, before Clauses 2 to 4 of the Bill can come into force, that the consent of Mauritius is not required for us to host third-party forces on Diego Garcia.

As I mentioned, I have the letter from the Ministers in which they helpfully clarify that permission from Mauritius is not required. However, I require the Minister to confirm that such notification is after the event. If notification is required before the event, that implies consent is required, or that the intimation of an objection by Mauritius is possible. That is why I seek the clarification.

We cannot have a situation where Mauritius can in any way object to which forces are present at the base. The operation of the base, including the matter of the basing of our allies, must be solely at the discretion of the United Kingdom. I would appreciate the Minister giving a guarantee that Mauritius will have no control whatever over the basing and overflight of other countries’ forces. Unusually, the Minister and I are perhaps nearly at consensus in idem here. If that is the case, why would the Secretary of State be reluctant to publish a statement?

Amendment 86 is another defence and security amendment. It seeks that Clauses 2 to 4 would not come into force until the Secretary of State has published a statement establishing that the obligation under Annex 1(2) of the treaty

“does not extend to aircraft and vessels which have landed or docked at the Base for the purposes of maintenance or refuelling prior to the armed attack on a third state”.

Annex 1(2) of the treaty is the provision that requires the United Kingdom

“to expeditiously inform Mauritius of any armed attack on a third State”.

As we have discussed, much has been made of what is meant by “expeditiously”. The Ministers’ letter to me stated that they are satisfied that this does not require the UK to seek the permission of Mauritius, nor for notification to be given prior to the event. That is helpful. The International Agreements Committee of this House has also concluded that it interprets “expeditiously” to mean

“as soon as reasonably practicable in the circumstances”.

I believe that the Minister gives her interpretation in good faith, but what of Mauritius’s interpretation? Does the Minister know whether the Mauritian Government share this view? If she does not currently know, and I quite accept that she may not, I would be happy for her to write to me to confirm the point.

Diego Garcia Military Base and British Indian Ocean Territory Bill

Debate between Lord Callanan and Baroness Goldie

Committee stage
Tuesday 25th November 2025 Lords Chamber

[Baroness Goldie (Con)]

My Lords, I did not expect to participate in this, but I was having a conversation earlier with my noble friend Lord Minto, who is very knowledgeable about corporate finance. He posed the question: is there anything in this whole arrangement that would stop Mauritius capitalising on the revenue stream that they have coming to them and selling that off to someone else?

[Lord Callanan (Con)]

I am sorry that my noble friend Lord Kempsell is not here to move his amendment, which I thought was a particularly good one.

We debated some of the financial aspects of the treaty on the first day in Committee. The Minister at that time asked to delay her remarks on those amendments to the appropriate group. I assume this is the group that she was referring to, so we all look forward to the fuller answer on the finances that she promised then.

The core contention of the Government is that the deal costs an average of £101 million a year and the present net value of payments under the treaty is therefore £3.4 billion. This has been challenged by my noble friends Lady Noakes and Lord Altrincham, but the Minister, rather than engaging in the substance of those challenges, has relied on the Government’s published figures and refused to explain why she believes those figures accurately reflect the cost of the deal.

The Minister has relied on the approval of the Government Actuary’s Department and simply argued that consistency was essential. These are typical deflections that, no doubt, many Ministers have used in previous cases, but they do not address the concerns of my noble friends. We know that the payments are front-loaded at £165 million for the first three years, and then £120 million for the next 10 years. After that point, it is index-linked. As my noble friend Lady Noakes set out at Second Reading, that will see the cash payments hitting more than £650 million a year by the end of the 99 years, depending, of course, on what indexation you use. With all those additional considerations, it is our contention that the true cost of the deal is not £3.4 billion, as claimed by Ministers, but something more like £35 billion.

So the question lands: why would the Government seek to play this down? If they are so delighted with the deal—if it is such a good deal for the British public that they keep claiming that they deliver for, as all government policies should surely be—then surely they would want to be open about the true cost of things. They brag about spending on every other area; they take every amount of money per year, cumulatively add it all up and then put it in a press release and brag to the British people about what a great amount they are spending in every area except for this one. Does the Minister think it is better that the country should know the full costings before the treaty comes into effect, or would she prefer that the UK tie itself into these vast annual payments first, before admitting what the true cost of the deal actually is?

We are clear that the British people deserve to know what their Government are signing up for. Ministers should engage with the detailed costings laid out by my noble friends Lady Noakes and Lord Altrincham, and the points made by my noble friend Lord Lilley, rather than hiding behind their pre-prepared lines. If they have nothing to hide, what is wrong with producing a report that we can all see and study and get checked by independent financial experts? Once Ministers have admitted the true cost of the deal, then they can start justifying the so-called benefits of the treaty against what the true cost actually is. I do not think that people would be impressed by arguments justifying that figure, but Ministers should do the decent thing and justify the real numbers openly and in public.