Question to the Ministry of Defence:

To ask the Secretary of State for Defence, how many stages of investment there will be as part of the Dreadnought submarine programme; and what the future phases of construction will entail.

The 2015 Strategic Defence and Security Review confirmed that the Dreadnought Programme would move away from a traditional single 'Main Gate' approach, as it was deemed inappropriate for a programme of this scale and complexity, and instead would operate a staged investment programme.

The first of these stages, Delivery Phase 1, started in September 2016; and construction formally began in October 2016 with the cutting of steel for the first submarine. The number of investment stages throughout the 20 year acquisition programme will be defined as the build progresses.

The phases of Dreadnought construction comprise: major steelwork being formed into units; installing and outfitting of systems and plant; integration and testing of systems; and sea trials culminating in acceptance into service.