 In February 2011, the Defence Secretary Liam Fox stated that four submarines would be needed if the UK was to retain a credible nuclear deterrent.On 18 May 2011 the British government approved the initial assessment phase for the construction of a new class of four submarines, paving the way for the ordering of the first long-lead items and preparations for the main build to begin in the future.This new class of submarine, now known as the "Dreadnought" class, will retain the current Trident II missiles, and will incorporate a new 'PWR3' nuclear reactor as well as technology developed for the nuclear-powered fleet submarines of the Royal Navy.