Question to the Ministry of Defence:

To ask the Secretary of State for Defence, whether his Department has examined options for cooperation with France on the M51.4 submarine‑launched missile.

The UK and France work closely together on a range of nuclear research and technology matters, including as part of the 2010 Teutates Treaty. Our deepening co-operation under the 2025 Northwood Declaration includes nuclear policy, capabilities and operations.

The UK will continue to rely on its Trident II D5 submarine launched ballistic missiles, which we procure from the United States, significantly reducing the cost of our nuclear deterrent capability. The Trident missile system remains the most reliable weapons system in the world and the government has absolute confidence that the UK’s deterrent remains effective, dependable, and formidable.