Question to the Ministry of Defence:

To ask the Secretary of State for Defence, what recent estimate he has made of the cost of (a) the SSN-AUKUS programme, (b) supporting the in-service (i) submarine and (ii) SSN fleet, (c) maintenance programmes on SSN submarines and (d) HM Naval Base Clyde in the 2022-23 financial year.

The SSN-AUKUS programme is currently in its design phase. A cost estimate will be substantiated once Class size requirements have been agreed and the programme enters its next phase, ready for manufacture.

I can confirm that in financial year (FY) 2022-23, the cost of in-service support and maintenance programmes for submarines was £594 million. Due to commercial sensitivities and consolidated management information, it is not possible to break out the cost of maintenance programmes from the cost of total in service support.

In FY 2022-23, the cost of His Majesty’s Naval Base Clyde was £278 million, including all infrastructure costs.