To ask the Secretary of State for Defence when he expects the concept design for the Trident successor submarines to be finalised; and what effect the delay in this process will have on the timetable for the delivery of the Trident successor submarines. (321415)

[holding answer 11 March 2010]: We need a few more months to ensure we take design decisions based on robust information. We do not expect this extension of the concept phase to affect the timetable for delivery of the successor submarine.