Question to the Ministry of Defence:

To ask the Secretary of State for Defence, what work has been carried out by the manufacturers of other Trident D5 II missiles to prevent reoccurrence since the missile was unable to complete its test after being launched as part of the 2016 Demonstration and Shakedown Operation exercise.

I refer the hon. Member to the answer I gave on 23 January to the hon. Member for North Durham (Kevan Jones) (Vol 620, Col 23). Details of the Trident weapon system and submarine operations must remain secret. The Government is in no doubt about the capability and effectiveness of the Trident missile system. HMS Vengeance successfully concluded her Demonstration and Shakedown Operation and returned to the operational cycle.