The US military has been using Britain's atomic weapons factory to carry out research into its own nuclear warhead programme, according to evidence seen by the Guardian.
US defence officials said that "very valuable" warhead research has taken place at the Atomic Weapons Establishment at Aldermaston in Berkshire as part of an ongoing and secretive deal between the British and American governments.
Last night, opposition MPs called for a full parliamentary inquiry into the extent of the collaboration at Aldermaston and campaign groups warned any such deal was in breach of international law. They added that it also undermined Britain's claim to have an independent nuclear weapons programme and meant British taxpayers were effectively subsidising America's nuclear programme.