Diego Garcia Military Base and British Indian Ocean Territory Bill

Lord Northbrook Excerpts

2nd reading
Tuesday 4th November 2025 Lords Chamber

[Lord Northbrook (Con)]

My Lords, I declare an interest as a member of the Chagos Islands APPG. I give its secretary, David Snoxell, credit for persevering with the cause over the years. Unfortunately, having reflected carefully on the issue and the treaty, I have come to disagree on the conclusions formed by many of the group. I now feel that Mauritius will unfairly benefit more from the treaty than the Chagossians will. Indeed, I now feel that this agreement is bad for our national security and financially a disaster.

Until recently, I was under several misapprehensions. First, I was led to believe that the International Court of Justice—ICJ—verdict that the island should be handed back to Mauritius was legally binding on the UK. Secondly, I had not realised that the UK had already paid Mauritius £3 million in 1965 to retain ownership of the Chagos Islands after Mauritian independence. Thirdly, I believed that the UK was bound by the United Nations Convention on the Law of the Sea—UNCLOS. Fourthly, I believed that we had to obey the diktat of the International Telecommunication Union—ITU—concerning the threat to the electromagnetic spectrum. Fifthly, I had underestimated the threat to the islands on the defence front from future restrictions on nuclear weapons and from encroachment by China, Russia and Iran. Sixthly, I am not sure that the guarantees and financial promises to the Chagossians will be honoured.

I will now deal with each of the above issues in turn. First, on the ICJ verdict, I have since discovered that, while from February 2017 the UK has accepted in declarations all judgments of the ICJ, it does not accept that they apply to any dispute with the Government of any country which is or has been a member of the Commonwealth.

Secondly, the payment of £3 million in 1965—over £80 million in today’s money—means that we should not be paying Mauritius again.

Thirdly, the UK is not legally bound by the decisions of the International Tribunal for the Law of the Sea. According to Dr Luke Evans, at Second Reading in the other place on 9 September,

“back in 2015, under annex VII, the tribunal agreed with the UK that sovereignty could not be determined by UNCLOS. This was a marine protection issue”.—[Official Report, Commons, 9/9/25; col. 818.]

Fourthly, as forensically examined by colleagues in the other place—Sir Jeremy Wright, Sir John Whittingdale and Mark Francois—it is clear that the ITU has no jurisdiction over the UK’s electromagnetic spectrum. The ITU treaty, to which we and others are a party, states specifically that the ITU has no authority over the allocation of military spectrum. Individual countries, not the ITU, make their own sovereign spectrum assignments in accordance with the radio regulations. The ITU has no legal authority over these assignments regardless of the country’s civilian or military classification of spectrum. Will the Minister please confirm this, in light of the fact that any judgment by the ICJ against us is not legally binding?

Fifthly, I want to focus on the defence threat to the West from this deal. The Pelindaba treaty, as already mentioned, to which Mauritius is a signatory, prohibits the stationing and storage of nuclear weapons, yet Ministers have failed to explain what that will mean in practice once sovereignty is transferred. Also, an element of the agreement involves a requirement for us to expeditiously inform Mauritius of any armed attack on a third state directly emanating from the base. Can the Minister tell us whether this means that it must be done before the armed attack?

The defence threat also comes from hostile powers in the region. The risk to Britain’s security is great. Diego Garcia is our most strategic and important base in the Indian Ocean, critical to our partnership with the United States, and vital to project influence in the Indo-Pacific. Yet the Bill leaves huge questions unanswered. What safeguards will prevent hostile powers such as China, Russia and Iran seeking a foothold in the archipelago once Britain steps back? Beijing already describes Mauritius as a partner with strategic advantages, and Mauritius could well join its belt and road initiative. Port Louis boasts of advancing co-operation with Russia. Iran, since the first Iran-Mauritius Economic Forum in 2022, has explored export and import opportunities and joint ventures in agriculture, fisheries, pharmaceutical industries and nanotechnology.

Sixthly, I want to focus on the situation for the Chagossians themselves after this treaty. The speeches at Second Reading by the Labour MP Peter Lamb and the Conservative MP Aphra Brandreth are very relevant on the subject. Peter Lamb, MP for Crawley, where many Chagossian exiles live, makes very relevant points, from which I shall quote directly:

“Although mention of the Chagossians is made in the wording of the deal, I remain concerned … that there are gaps that leave the Chagossian people at risk. While there is the option for Chagossians to be allowed by the Mauritian Government to return to the islands, there is no requirement in the deal that that happens. There is no guarantee that any Chagossian who does return to the archipelago will not face restrictions that prevent permanent habitation, even at a subsistence level of economic activity. There is no guarantee at this time that the trust fund that is being created will be in the control of the Chagossians and used exclusively to address the consequences of their forcible removal from the islands. There is no guarantee that returning Chagossians will not face a 10-year prison sentence for questioning Mauritian territorial integrity through taking on British citizenship”.


Aphra Brandreth adds another key point on the issue, saying:

“The Government must … take the opportunity to implement a recommendation put forward by the House of Lords International Relations and Defence Committee and International Agreements Committee … that looked at the treaty. They urged the Government to ‘Enhance Chagossian engagement by establishing a formal consultation mechanism with the Chagossian community to monitor the Agreement’s implementation and ensure their meaningful inclusion in decision-making.’ Will the Minister confirm whether that recommendation will be implemented?”


Further, she states that

“the … trust fund, established as part of the UK-Mauritius treaty and financed by the UK, is to be distributed solely under the control of Mauritius, yet the Bill contains no provisions to monitor whether the rights of British Chagossians are upheld or to create any statutory oversight of the trust fund. Have Ministers secured from the Government of Mauritius any firm commitment that British Chagossians will have a formal role in the oversight and decision making regarding the fund? Indeed, why was a model of joint governance not agreed, ensuring that British Chagossians themselves have a voice in how the fund is governed and can benefit directly from it?”.—[Official Report, Commons, 9/9/25; cols. 773, 812.]

In conclusion, this is a terrible deal for the UK, giving away full ownership of a vital defence asset and paying the Mauritian Government an extraordinary sum of £34 billion in cash terms to lease it back. I have shown how the key pillars of the Government’s argument for the necessity of doing this do not stand up. These are, namely, the ICJ judgment, the ITLOS argument and the electromagnetic spectrum. I reiterate that the Chagossians have certainly not been looked after in this deal, hence I would have strongly supported the noble Lord, Lord Callanan, in his amendment.