Question to the Ministry of Defence:
To ask the Secretary of State for Defence, on how many days during 2017 there were no (a) Astute class submarines, (b) Trafalgar class submarines and (c) submarines of any class available for patrol.
There are three Astute Class and three Trafalgar Class submarines currently in service at various stages of their operating cycle.
It is UK policy that we do not comment on matters relating to submarine activity or operations as to do so would, or would be likely to, prejudice the capability, effectiveness or security of the Armed Forces.