§ Harry Cohen
To ask the Secretary of State for Defence what his estimate is of the cost to the United Kingdom of a possible ballistic missile defence system involving new weapons and the latest technology; what assessment he has made of the benefits of the system; what his policy is on the response of the UK Government to a country firing a ballistic missile at the United Kingdom; what his estimate is of a likely non-country actor obtaining and firing a ballistic missile at the United Kingdom; and if he will make a statement. 
§ Mr. Hoon
As I told the House on 17 October 2002,Official Report, column 503, it is right that we recognise the potential contribution of missile defence to a comprehensive strategy to deal with the threat from ballistic missiles. No realistic cost estimates can be made at this stage. The United States Government has made no specific decisions on the overall architecture of a US missile defence system. No decision has been taken on the acquisition of a missile defence system by the UK.
The firing of a ballistic missile at the UK from any source would be a clear act of aggression which would receive a proportionately serious response. We currently assess the possibility of a non-state actor obtaining and launching a ballistic missile at the United Kingdom as remote.