Dr Julian Lewis: In the inexplicable absence of any Liberal Democrat on his feet, may I ask my right hon. Friend whether he agrees that as an alternative to Trident, the idea of putting nuclear-armed cruise missiles on Astute-class submarines would be more expensive and less effective, would put the submarines at risk and, because one cannot know what sort of warhead is on a cruise missile until it has landed, could start World War Three by accident? Does he agree that apart from that, it is a great Liberal Democrat idea?

[The Secretary of State for Defence (Dr Liam Fox): As the House will know, when we considered the entire issue in 2006 and 2007 we looked at options for other systems, including cruise missiles, silo-based missiles and air-launched weapons. Those other options were discounted due to effectiveness and cost. That analysis has not changed, and alternative systems will not be considered as part of the value-for-money review.]