§ Mr. Simon Hughes
To ask the Secretary of State for Defence what are the procedures for informing foreign Governments if an accident involving British-controlled nuclear weapons had occurred on their soil or within their 345W borders; when these procedures were adopted; and under what circumstances foreign Governments have had to be warned of such accidents. 
§ Mr. Soames
In ratifying the International Atomic Energy Agency convention of 26 September 1986 on early notification of a nuclear accident, the United Kingdom Government undertook to notify the IAEA and affected states in the event of an accident to military facilities or equipment which had or might have consequences that could be of radiological safety significance for another state. Separate bilateral arrangements have also been concluded as appropriate: the terms of these are classified. There has never been an accident involving a UK nuclear weapon which has required a foreign Government to be informed under these arrangements.