Question to the Ministry of Defence:

To ask the Secretary of State for Defence, what estimate his Department has made of the potential cost to (a) Devonport Royal Dockyard, (b) Rolls Royce in Derby and (c) elsewhere for refuelling operations to extend the lifespan of the Vanguard-class submarines until the Dreadnought submarines are built.

A decision on whether to refuel HMS Victorious is to be made later this year and therefore estimated costs related to the refuelling operations have yet to be finalised.

There are currently no plans to refuel HMS Vigilant or HMS Vengeance.