Question to the Ministry of Defence:

To ask the Secretary of State for Defence, what the (a) procurement and (b) life-cycle costs are for a Royal Navy Astute Class submarine.

It is not possible to identify a single unit cost for an Astute Class submarine as Boats one to three (Astute, Ambush, and Artful) were contracted as a batch, with the rest of the class subject to separate contractual arrangements. However, as an example of the main costs involved, the whole-boat contract for Agincourt, the seventh and last boat in the class, announced in May 2018, was £1.5 billion. This covers the totality of work involved in the boat build, including test and commissioning. The procurement costs include initial support provisioning, however, in-service support costs of a submarine will vary with the individual platform material state. These costs form part of wider submarine maintenance contracts and are not easily identifiable separately and could be provided only at disproportionate cost.