Written questions by Francois.

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.

With reference to paragraph 3(h) of Article 2 of the document entitled UK/Mauritius: Agreement concerning the Chagos Archipelago including Diego Garcia (CS Mauritius No.1/2025), what steps he plans to take to ensure the Government of Mauritius's regulation of the provision of electronic communications services does not impact the communication systems of Naval Support Facility Diego Garcia.

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 Commission, which is described in Annex 3 of the Treaty. There can be no decisions without UK agreement.

With reference to paragraph 1(b)(iii) of Annex 1 of the document entitled UK/Mauritius: Agreement concerning the Chagos Archipelago including Diego Garcia (CS Mauritius No.1/2025), what steps he plans to take to ensure the exclusive command and control over military personnel in Diego Garcia as defined in Article 19 of the Agreement.

The UK has full command and control over UK military personnel on Diego Garcia. There are no means for Mauritius to obtain command and control over UK military personnel as a result of the treaty.

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), what estimate he has made of the cost to the public purse supporting the Government of Mauritius in (a) establishing and (b) managing the Chagos Archipelago Marine Protected Area over the next ten years.

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 paragraph 2 of Annex 1 of the document entitled UK/Mauritius: Agreement concerning the Chagos Archipelago including Diego Garcia (CS Mauritius No.1/2025), if he will define the term expeditiously inform; and what protocols are in place regarding the (a) timeframe and (b) nature of such communications with the Government of Mauritius.

Any notification will take place after the event and will not require the UK to divulge sensitive information. Agreement to inform a host nation about military action from their territory is standard practice in basing arrangements. Additionally, the UN Charter has a requirement to notify the UN of military action taken in self-defence.

With reference to Article 6 of the document entitled UK/Mauritius: Agreement concerning the Chagos Archipelago including Diego Garcia (CS Mauritius No.1/2025), what steps he will take to prevent unauthorised access to Diego Garcia as defined in Article 19 of the Agreement.

Under the treaty, Mauritius will have the ability to conduct resettlement on any island in the Chagos Archipelago other than Diego Garcia. The UK has no intention of constraining resettlement activity, but has negotiated an effective veto over any activity that presents a clear and direct threat to the base on Diego Garcia. The United Kingdom controls access, and therefore authorisations, for all persons permitted to be on Diego Garcia.

With reference to Article 3 of the document entitled UK/Mauritius: Agreement concerning the Chagos Archipelago including Diego Garcia (CS Mauritius No.1/2025), how his Department will co-operate with the Government of Mauritius on maritime security, including efforts to combat (a) trafficking and (b) piracy.

Mauritius and the United Kingdom will cooperate on matters relating to maritime security. Our contribution will focus on providing training and building institutional partnerships. This will contribute to preserving the safety, security, stability and prosperity of the Indian Ocean region and will support the future operation of the Base on Diego Garcia.

With reference to Article 5 of the document entitled UK/Mauritius: Agreement concerning the Chagos Archipelago including Diego Garcia (CS Mauritius No.1/2025), whether his Department has contingency plans to address potential restrictions on operations at Naval Support Facility Diego Garcia in the event of the Government of Mauritius citing infringements of the Mauritian environmental laws.

The United Kingdom is not bound by Mauritian environmental law. Under Article 5, the UK will apply applicable international environmental law with due regard to applicable Mauritian environmental laws; this reflects the long-standing Defence policy of applying both our own and our host nations' environmental standards so far as it is reasonably practicable.

With reference to paragraph 5 of Annex 1 of the document entitled UK/Mauritius: Agreement concerning the Chagos Archipelago including Diego Garcia (CS Mauritius No.1/2025), what estimate he has made of the cost of providing assistance to the Government of Mauritius to (a) monitor, (b) detect, and (c) adjudicate security risks and (d) conduct security reviews over the first ten years of the Agreement.

As set out in the new UK-Mauritius Strategic Partnership Framework, Mauritius and the United Kingdom will cooperate on matters relating to maritime security. Further engagement on the details of this cooperation with Mauritius is ongoing. Securing the future operation of the Base on Diego Garcia was the objective of the treaty with Mauritius and that will remain the objective in the work to operationalise the treaty.

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.

With reference to paragraph 8(e) of Annex 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 assist the Government of Mauritius prevent unlicensed commercial fishing in Diego Garcia as defined in Article 19 of the Agreement.

In conjunction with the steps taken elsewhere in Government, the Ministry of Defence will assess the capability of Mauritius to secure its Exclusive Economic Zone and will provide targeted support, including through training, to strengthen efforts to counter illegal, unregulated and unreported fishing and support a secure and prosperous Indian Ocean region.

With reference to Article 15 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 arbitration procedures under paragraph 4.

The procedures concerning paragraph 4 of Article 15 are set out in Annex 4.

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 procedures his Department plans to use to notify the Government of Mauritius of the (a) maintenance and (b) upgrade of equipment in the Chagos Archipelago beyond Diego Garcia as defined in Article 19 of the Agreement.

The Joint Commission, as set out in Annex 3(6)a of the treaty, has the remit of serving as a forum for dialogue between the Parties, including the exchange of information regarding the security and protection of, and activities within, the Chagos Archipelago.

With reference to Article 3(2)(c) 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 maintain the (a) defence and (b) security of Diego Garcia as defined in Article 19 of the Agreement; and how his Department will coordinate this with the Government of Mauritius.

The objective of the treaty and the substantive obligation on both parties is the long-term, secure and effective operation of the base on Diego Garcia. Therefore, the treaty itself is designed to secure and protect the base and every obligation in the treaty is read in light of this obligation. This includes the fact that the UK has responsibility for the defence and security on Diego Garcia. Implementation measures, including the Strategic Partnership Framework, are being constructed against this treaty premise; Ministry of Defence relations with the Government of Mauritius will be supported in country by establishing a new non-Resident Defence Adviser position.

With reference to paragraph 2 of Annex 2 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 potential agreements on the jurisdiction of US personnel in Diego Garcia as defined by Article 19 of the Agreement.

With reference to paragraph 2 of Annex 2 of the document entitled UK/Mauritius: Agreement concerning the Chagos Archipelago including Diego Garcia (CS Mauritius No.1/2025), the jurisdiction of US personnel on Diego Garcia is set out in the UK-US Exchange of Notes (EoN).

With reference to paragraph 8 of Annex 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 provide assistance to the Government of Mauritius to help prevent unlicensed commercial fishing around Diego Garcia as defined in Article 19 of the Agreement; and what estimate has he made of the cost to the public purse of such assistance over the next ten years.

In conjunction with the steps taken elsewhere in Government, the Ministry of Defence will assess the capability of Mauritius to secure its Exclusive Economic Zone and will provide targeted support, including through training, to strengthen efforts to counter illegal, unregulated and unreported fishing and support a secure and prosperous Indian Ocean region.

With reference to paragraph 6(b) of Annex 1 of the document entitled UK/Mauritius: Agreement concerning the Chagos Archipelago including Diego Garcia (CS Mauritius No.1/2025), what steps he plans to take to ensure that the UK's submission does not compromise the Naval Support Facility Diego Garcia’s operations.

The UK is not obligated under the treaty to provide any operationally sensitive detail to Mauritius. Any submissions made under Annex 1 paragraph 6 will undergo assessment by the UK in consultation with the US to ensure operations are not compromised.

With reference to paragraph 8(a) of Annex 2 of the document entitled UK/Mauritius: Agreement concerning the Chagos Archipelago including Diego Garcia (CS Mauritius No.1/2025), what estimate he has made of the cost to the public purse of providing assistance to the Government of Mauritius in the provision of (a) facilities and (b) amenities for Mauritian law enforcement officials on Diego Garcia as defined in Article 19 of the Agreement over the next ten years.

As per paragraph 10 of Annex 2, the UK and Mauritius will be agreeing separate arrangements and operating procedures as necessary to assist and facilitate the exercise of Mauritian jurisdiction in respect to paragraph 8. There will be no additional facilities on island to enable Mauritian jurisdiction.

With reference to paragraph 1(b)(viii) of Annex 1 of the document entitled UK/Mauritius: Agreement concerning the Chagos Archipelago including Diego Garcia (CS Mauritius No.1/2025), what notification protocols his Department will establish for (a) non-United Kingdom and (b) non-United States aircraft accessing Diego Garcia as defined in Article 19 of the Agreement.

Aircraft accessing Diego Garcia will maintain standard notification practices for flight information regions, which exist in the Indian Ocean flight information zone and other international flight information zones.