Written questions by Francois.

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 security protocols his Department will establish for (a) non-United Kingdom and (b) non-United States vessels accessing Diego Garcia as defined in Article 19 of the Agreement.

This provision enables the United Kingdom to permit and control access to Diego Garcia by partner states. No further security protocols are required.

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 Article 5(3) of the document entitled UK/Mauritius: Agreement concerning the Chagos Archipelago including Diego Garcia (CS Mauritius No.1/2025), what steps his Department is planning to take to co-operate with the Government of Mauritius on (a) illegal, (b) unreported, and (c) unregulated fishing in the Chagos Archipelago.

In conjunction with the steps taken elsewhere in Government, the Ministry of Defence will support closer collaboration between the UK and Mauritius in this area by providing training which boosts Mauritian maritime security capabilities and maritime domain awareness.

With reference to paragraph 1(a) of Annex 1 of the document entitled UK/Mauritius: Agreement concerning the Chagos Archipelago including Diego Garcia (CS Mauritius No.1/2025), whether the Agreement permits (a) access, (b) basing, and (c) overflight rights for (i) United Kingdom and (ii) United States forces in the (i) territory, (ii) waters and (iii) airspace of the Government of Mauritius outside of Diego Garcia as defined in Article 19 of the Agreement.

In respect of the Chagos Archipelago beyond Diego Garcia, vessels and aircraft of the United Kingdom and the United States of America shall have unrestricted rights of overflight, navigation and undersea access.

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.

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 steps his Department plans to take to provide assistance to the Government of Mauritius for (a) monitoring and (b) detecting security risks in the Chagos archipelago.

Work on the details to implement the treaty is ongoing across Government, including engagement with Mauritius as appropriate. Defence’s contribution will centre on developing Mauritian capability to provide maritime security through improved maritime domain awareness and broader capability development.

With reference to paragraph 8(d) 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 in the (a) arrest in and (b) transfer of prisoners from Diego Garcia as defined in Article 19 of the Agreement.

The UK will support the exercise of jurisdiction of Mauritius on Diego Garcia over (i) Mauritian nationals who are not members of UK Armed Forces or US personnel, and (ii) all persons not connected to the operation of the Base. This ensures that Mauritius has jurisdiction over any future illegal migration to the island, closing off a dangerous and costly immigration route to the UK.

With reference to the document entitled UK/Mauritius: Agreement concerning the Chagos Archipelago including Diego Garcia (CS Mauritius No.1/2025), how he will ensure the (a) security and (b) operational continuity of Comprehensive Nuclear-Test-Ban Treaty Organisation monitoring stations on Diego Garcia under Mauritian sovereignty.

The United Kingdom shall continue to be responsible for the administration and facilitation of maintenance of the Comprehensive Nuclear-Test-Ban Treaty Organisation monitoring stations on Diego Garcia. The arrangements are described in the International Organisations exchange of letters.

With reference to paragraph 8(b) 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 for the carrying out of all necessary investigations into offences; and what estimate has he made of the cost to the public purse of such assistance 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 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 ensure the resettlement programme does not impact the security of operations at Naval Support Facility Diego Garcia.

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.

With reference to Article 2(3)(g) of the document entitled UK/Mauritius: Agreement concerning the Chagos Archipelago including Diego Garcia (CS Mauritius No.1/2025), what steps his Department is taking to ensure that military operations in Diego Garcia as defined in Article 19 of the Agreement are not impeded by compliance with the environmental laws of the Government of Mauritius.

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 3(e) of Annex 1 of the document entitled UK/Mauritius: Agreement concerning the Chagos Archipelago including Diego Garcia (CS Mauritius No.1/2025), what steps his Department is planning to ensure the departure of any security force from the Chagos Archipelago whose continued presence is not agreed under paragraph 3(d).

The Treaty clearly states a strict prohibition on foreign security forces operating in the Chagos Archipelago without UK consent. If a security force is operating in the Chagos Archipelago without the joint agreement of the UK and Mauritius, we will cooperate as necessary, to prevent or otherwise bring to an end such activity.

Whether the costs for the UK/Mauritius: Agreement concerning the Chagos Archipelago including Diego Garcia [CS Mauritius No.1/2025] are accounted for under his Department's Resource Departmental Expenditure Limit; and what estimate he has made of the potential impact of these costs on (a) his Department's operational budget and (b) the Government’s commitment to increase defence spending to 2.5% of GDP by April 2027.

These are being considered as part of the wider Government engagement on the second phase of the Spending Review, which concludes on 11 June 2025.

What estimate he has made of the cost of the investigation into unauthorised social media use by a British Army regiment.

The Army has investigated a number of social media posts which were published in error and without correct authorisation. Those posts have been removed and updated guidance has been issued to Regimental HQs on the appropriate use of regimental websites and social media pages. This work has been conducted as part of Army routine business, with no additional costs incurred.

Whether the findings of the investigation into unauthorised social media use by a British Army regiment will be made publicly available.

The Army has investigated a number of social media posts which were published in error and without correct authorisation. Those posts have been removed and updated guidance has been issued to Regimental HQs on the appropriate use of regimental websites and social media pages. This work has been conducted as part of Army routine business, with no additional costs incurred.

What the terms of reference are for the investigation into unauthorised social media posts by a British Army regiment.

The Army has investigated a number of social media posts which were published in error and without correct authorisation. Those posts have been removed and updated guidance has been issued to Regimental HQs on the appropriate use of regimental websites and social media pages. This work has been conducted as part of Army routine business, with no additional costs incurred.

What his planned timeline is for concluding the investigation into unauthorised social media use by a British Army regiment; and whether he plans to make a Statement to Parliament on the findings of the investigation.

The Army has investigated a number of social media posts which were published in error and without correct authorisation. Those posts have been removed and updated guidance has been issued to Regimental HQs on the appropriate use of regimental websites and social media pages. This work has been conducted as part of Army routine business, with no additional costs incurred.

Who is leading the investigation into unauthorised social media use by a British Army regiment.

The Army has investigated a number of social media posts which were published in error and without correct authorisation. Those posts have been removed and updated guidance has been issued to Regimental HQs on the appropriate use of regimental websites and social media pages. This work has been conducted as part of Army routine business, with no additional costs incurred.

What budget has been allocated to Project Eve; what the (a) current and (b) anticipated future spend are for that project; and what steps he is taking to ensure interoperability with the (i) Army’s and (ii) Royal Navy’s communications systems.

As part of the Commando Force (CF) Programme, £99.78 million has been spent on spiral development and fielding of the EVE digital backbone capability. A further £56 million budget for EVE is approved as future spend, to enable interoperable development and scaling to Littoral Strike Group level by December 2030. EVE, developed by the Royal Navy, has been a pathfinder in Defence digital innovation. EVE has been fielded by the Army’s Very High Readiness forces, as part of the Land Environment Tactical Communications and Information Systems programme. EVE is an integral part of the wider Royal Navy Strike Network design.

What the cost is of the Crye Precision uniform programme; and whether a replacement combat uniform programme is planned.

The Royal Navy have spent £15.803 million to date regarding the total procurement of Crye Precision uniforms. A future uniform programme is in development.