Written questions by Francois.

Commonwealth and Development Affairs, with reference to Article 11 of the UK/Mauritius Agreement concerning the Chagos Archipelago including Diego Garcia, published on 22 May 2025, whether he plans to put in place mechanisms to help ensure that the trust fund is (a) managed transparently and (b) is used to support the Chagossian community.

As outlined in the Explanatory Memorandum, the UK will capitalise a Trust Fund established by Mauritius for the benefit of Chagossians. The Mauritian government will oversee the fund, but the UK will work with them to develop its details during implementation discussions.

Commonwealth and Development Affairs, with reference to Article 19 and Annexes 5 and 6 of the document entitled UK/Mauritius: Agreement concerning the Chagos Archipelago including Diego Garcia (CS Mauritius No.1/2025), what steps his Department plans to take with the Government of Mauritius to determine the precise maritime zones of (a) the Chagos Archipelago and (b) Diego Garcia.

The UN Convention on the Law of the Sea (UNCLOS) sets out the international legal basis on which States can establish coastal baselines and maritime zones, including a territorial sea and exclusive economic zone. Once the Treaty enters into force, the determination or delimitation of any maritime zones around the Chagos Archipelago will be a matter for Mauritius, in accordance with UNCLOS. The UK will have rights, as set out in the Treaty in relation to a 12 nautical mile zone surrounding the island of Diego Garcia, and in relation to the zone between 12 and 24 nautical miles surrounding the island of Diego Garcia.

Commonwealth and Development Affairs, with reference to paragraph 3 of the Exchange of Letters concerning the Implementation and Interpretation of Article 11 of the UK/Mauritius Agreement concerning the Chagos Archipelago including Diego Garcia, published on 22 May 2025, whether he plans to put in place mechanisms to monitor Mauritius’ resettlement programme on islands other than Diego Garcia to ensure compliance with international human rights standards.

Under the agreement, Mauritius will be able to resettle the islands, other than Diego Garcia. It will be for Mauritius to set the terms of and manage any future resettlement. As fellow commonwealth members we expect Mauritius to ensure compliance, like the UK, with high human rights standards, in line with our shared international obligations.

Commonwealth and Development Affairs, with reference to Article 5(2) of the document entitled UK/Mauritius: Agreement concerning the Chagos Archipelago including Diego Garcia (CS Mauritius No.1/2025), whether he has made an estimate of the cost to the public purse of the financial contribution to the Government of Mauritius's Marine Protected Area; and if he will set out these will be accounted for in his Department's 2025/26 budget.

The Blue Belt Programme, which is funded by the Foreign, Commonwealth and Development Office, currently supports BIOT to manage the current Marine Protected Area. As the Treaty states, the terms of the management and support provided by the UK to Mauritius to establish and manage the Chagos Archipelago Marine Protected Area will be agreed between the Parties by a separate written instrument, as part of implementation of the Agreement.

Commonwealth and Development Affairs, with reference to paragraphs 1(a) to 1(c) of Article 11 of the document entitled UK/Mauritius: Agreement concerning the Chagos Archipelago including Diego Garcia (CS Mauritius No.1/2025), what estimate his Department has made of the net present value assuming a 2% inflation rate of the total amounts payable of the (a) annual sum, (b) capitalisation of a Trust Fund and (c) multi-year funding as part of a development framework.

Full details of the methodology are set out in the Explanatory Memorandum laid alongside the Treaty. We have published the full costs alongside the Treaty and laid them in the House. The figures are verified by the Government Actuary's Department, drawing on long-established methodology used under this government and previous governments.

Commonwealth and Development Affairs, with reference to paragraph 3 of Article 2 of the document entitled UK/Mauritius: Agreement concerning the Chagos Archipelago including Diego Garcia (CS Mauritius No.1/2025), what steps his Department plans to take to ensure that seabed exploration by the Government of Mauritius's does not impact the undersea cable operations of (a) Naval Support Facility Diego Garcia and (b) Diego Garcia as defined in Article 19 of the Agreement.

Article 3(2) of the treaty clearly states that Mauritius cannot undermine, prejudice or otherwise interfere with the long-term, secure and effective operation of the Base on Diego Garcia, and that Mauritius shall cooperate to that end. The US supports the Treaty, with US Secretary of State Rubio publicly noting that the Treaty "secures the long-term, stable, and effective operation of the joint U.S.-UK military facility at Diego Garcia".

Commonwealth and Development Affairs, with reference to Article 2 of the UK/Mauritius Agreement concerning the Chagos Archipelago including Diego Garcia, published on 22 May 2025, if he will make an assessment of the potential impact of the agreement on the UK’s strategic role in the North Indian Ocean Hydrographic Commission.

The International Organisations exchange of letters that was laid alongside the treaty states clearly that the UK's membership of the North Indian Ocean Hydrographic Commission (NIOHC) will change from a 'Full Member' to an 'Associate Member' following entry-into-force of the Diego Garcia Base Treaty. As an 'Associate Member' the UK will continue to be engaged with this important regional forum.

Commonwealth and Development Affairs, with reference to Article 11 of the document entitled UK/Mauritius: Agreement concerning the Chagos Archipelago including Diego Garcia (CS Mauritius No.1/2025) and the Exchange of Letters concerning Article 11 of the Agreement between the Government of the United Kingdom and the Government of the Republic of Mauritius concerning the Chagos Archipelago, which departments will fund the payments for the economic partnership including the (a) annual payments and (b) 25-year development framework grants; and whether these funds will be classified as development aid.

The costs associated with the deal will be split between the Ministry of Defence and the Foreign, Commonwealth and Development Office. None of the funds will be classed as development aid.

Commonwealth and Development Affairs, with reference to Article 4 of the document entitled UK/Mauritius: Agreement concerning the Chagos Archipelago including Diego Garcia (CS Mauritius No.1/2025), what steps he is taking to ensure compliance with international law does not restrict (a) operational capabilities and (b) weapons deployment in Diego Garcia as defined in Article 19 of the Agreement.

The agreement protects the operations on Diego Garcia to ensure the security of the UK and our allies, which is why it has been welcomed by the US and other 5 Eyes partners.The UK will ensure all operations on Diego Garcia will continue to comply with its international law obligations, as it does on all military bases and all defence operations.

Commonwealth and Development Affairs, with reference to paragraph 3(d) of Annex 1 of the document entitled UK/Mauritius: Agreement concerning the Chagos Archipelago including Diego Garcia (CS Mauritius No.1/2025), what criteria will be used to determine authorisations permitting the presence of non-United Kingdom, non-United States or non-Mauritian security forces, either civilian or military in the Chagos Archipelago beyond Diego Garcia as defined in paragraph 11 of Annex 1.

The authorisation of any non-UK, non-US or non-Mauritian security forces will be agreed jointly between the UK and Mauritius. This means that it can only happen if the UK agrees. Our approach on that will be determined by an analysis of whether the presence would risk undermining, prejudicing or otherwise interfering with the long-term, secure and effective operation of the Base.

Commonwealth and Development Affairs, with reference to Article 11(1)(b) of the document entitled UK/Mauritius: Agreement concerning the Chagos Archipelago including Diego Garcia (CS Mauritius No.1/2025) and the Exchange of Letters concerning Article 11 of the Agreement between the Government of the United Kingdom and the Government of the Republic of Mauritius concerning the Chagos Archipelago, whether beneficiaries of the trust fund established for Chagossians will include (a) British Chagossians and (b) Mauritian citizens; and if he will set out the criteria that will govern the determination of eligibility.

As outlined in the Explanatory Memorandum, the UK will capitalise a Trust Fund established by Mauritius for the benefit of Chagossians. The Mauritian Government will oversee the fund, but the UK will work with them to develop its details during implementation discussions. Separately, Chagossian communities in the UK will continue to benefit from projects delivered by the UK Government.

Commonwealth and Development Affairs, with reference to paragraph 3(c) of Annex 1 of the document entitled UK/Mauritius: Agreement concerning the Chagos Archipelago including Diego Garcia (CS Mauritius No.1/2025), how the (a) joint management and (b) use of the electromagnetic spectrum in the Chagos Archipelago beyond Diego Garcia will be agreed

The UK has unrestricted ability to control and manage the electromagnetic spectrum for Diego Garcia and the surrounding 12 nautical miles. Decisions related to the electromagnetic spectrum beyond Diego Garcia will be taken jointly by the UK and Mauritius at the Joint Commision, which is described in Annex 3 of the Treaty. There can be no decisions without UK agreement.

Commonwealth and Development Affairs, with reference to Article 4 of the document entitled UK/Mauritius: Agreement concerning the Chagos Archipelago including Diego Garcia (CS Mauritius No.1/2025), whether the implementation of the Agreement complies with the Treaty of Pelindaba including with respect to Naval Support Facility Diego Garcia.

The United Kingdom is not a Party to the Pelindaba Treaty, although it is a Party to Protocols I and II. The United Kingdom will ensure all operations on Diego Garcia will continue to comply with its obligations under applicable international law.

Commonwealth and Development Affairs, with reference to paragraph 3(b) of Annex 1 of the document entitled UK/Mauritius: Agreement concerning the Chagos Archipelago including Diego Garcia (CS Mauritius No.1/2025), what equipment located in the Chagos archipelago beyond Diego Garcia requires notification to the Government of Mauritius before (a) maintenance and (b) upgrades are conducted; and what procedures will govern the (i) content and (ii) timing of such notifications.

There are a range of vital facilities and capabilities on the base on Diego Garcia and the surrounding area that keep Britain safe. We do not discuss these publicly for security reasons.

Commonwealth and Development Affairs, with reference to Article 10 of the document entitled UK/Mauritius: Agreement concerning the Chagos Archipelago including Diego Garcia (CS Mauritius No.1/2025), what discussions he has had with his United States counterpart on United States forces at Naval Support Facility Diego Garcia prioritising the employment of suitably qualified Mauritian (i) nationals and (ii) companies as contractors.

The United States has welcomed the Diego Garcia Base Treaty. Defence Secretary Pete Hegseth stated that it "secures the operational capabilities of the base and key US national security interests in the region". We have worked closely with the US in securing this historic Treaty and will continue to work closely in its implementation.

Commonwealth and Development Affairs, with reference to Article 18 of the document entitled UK/Mauritius: Agreement concerning the Chagos Archipelago including Diego Garcia (CS Mauritius No.1/2025), if he will set out the (a) internal requirements and (b) procedures that the UK must complete for the Agreement’s entry into force; and what his planned timeline is for the completion of these steps.

The explanatory memorandum in sections 4 and section 5 sets out the process for both Entry into force and implementation.

Commonwealth and Development Affairs, with reference to paragraph 10 of Annex 1 of the document entitled UK/Mauritius: Agreement concerning the Chagos Archipelago including Diego Garcia (CS Mauritius No.1/2025), what mechanism will his Department use to initiate high-level consultations.

High-level consultations can be requested by either party through the mechanism of the Joint Commission or, in the event of any urgent concerns, through their respective High Commissions.

Commonwealth and Development Affairs, with reference to the document entitled UK/Mauritius: Agreement concerning the Chagos Archipelago including Diego Garcia (CS Mauritius No.1/2025), if will list the measures in the Agreement that address the wrongs of the past as stated in the preamble to that Agreement; and what estimate has he made of the cost to the public purse of those measures over the next ten years.

The costs of the Treaty have been published in the Finance Exchange of Letters, laid in Parliament together with the Treaty on 22 May.

Commonwealth and Development Affairs, with reference to Article 3(3) of the document entitled UK/Mauritius: Agreement concerning the Chagos Archipelago including Diego Garcia (CS Mauritius No.1/2025), how his Department plans will co-operate with the Government of Mauritius on trafficking in narcotics; and what estimate has he made of the cost to the public purse of such co-operation over the next ten years.

The new UK-Mauritius Strategic Partnership Framework will provide a comprehensive mechanism for delivering for the UK and Mauritius, including on areas such as narco-trafficking. UK and Mauritian Ministers will meet in the coming months to finalise the partnership and will then meet in an Annual Strategic Dialogue. This will review and keep evolving the Framework as necessary to support the security and prosperity of our countries into the future.

Commonwealth and Development Affairs, with reference to Article 11 of the document entitled UK/Mauritius: Agreement concerning the Chagos Archipelago including Diego Garcia (CS Mauritius No.1/2025), what oversight the UK plans to ensure the Government of Mauritius will use the grants to (a) promote the ongoing economic development and (b) welfare of (i) Mauritius and (ii) its people.

Full details of the mechanisms of use for the development framework grant will be agreed between the UK and Mauritius during the implementation period, before the first payment of the grant in year 4 of the Agreement.