Ssn20 23. Mr. Menzies Campbell To ask the Secretary of State for Defence if it is the intention of Her Majesty's Government to introduce the SSN20 into service within the Royal Navy; and if he will make a statement. Mr. Kenneth Carlisle My right hon. Friend announced on 25 July that we intend to maintain around 12 nuclear-powered submarines in service. Following the completion of feasibility studies for SSN20, we are considering the procurement plans needed to sustain this force level in the longer term.