To ask the Secretary of State for Defence if any information on the implementation of the 1958 Anglo-American mutual defence agreement on atomic energy matters has been withheld under sections 3(4) or 5(1) of the Public Records Act 1958. [32490]

A number of papers relating to the early years of the UK nuclear programme are closed under the Public Records Acts. It is likely that many of these involve matters relating to the 1958 UK-US mutual defence agreement, but to establish exactly what is held would involve disproportionate cost.