Question to the Ministry of Defence:

To ask the Secretary of State for Defence, whether the Royal Navy is required to obtain the (a) agreement and (b) authorisation of a civilian police force before (i) intercepting and (ii) challenging a foreign military vessel suspected of posing a threat to national security within the United Kingdom’s territorial sea; and what legal and operational guidance governs the responsibilities of the Royal Navy and civilian police in such circumstances.

The Royal Navy works with the Home Office, civilian police and partners across government to protect UK territorial waters, and respond to threats.

Responsibilities and authorisations depend on the circumstances and proposed action. Defence may support civilian authorities through established Military Aid to the Civil Authorities arrangements, while any exercise of maritime law-enforcement powers require a legal basis and must be undertaken by authorised personnel.

Royal Navy Police may exercise specified maritime enforcement powers in defined circumstances. Any review or change must reflect operational needs, applicable law and the UK's different jurisdictions. As the threat picture changes, the MOD supports HMG efforts to ensure the continued security of the UK and our territorial waters, including primary legislation as necessary.