Government Code and Cypher School: Signals Intelligence Passed to the Prime Minister, Messages and Correspondence

A file of signals intelligence reports, messages, and correspondence issued by the Government Code and Cypher School and sent by the head ('C') of the Secret Intelligence Service (MI6) to the Prime Minister, Winston Churchill. This file contains a message from C to the Assistant Chief of Air Staff Intelligence (ACASI) with the Prime Minister's (PM's) comments for the Chief of the Air Staff (CAS) on the following reports: on South-east Europe: that the German Air Force (GAF) receives extra mine-sweeping forces for the Danube, on April 22; and from the German secret service in Bucharest on the need for urgent action to counter mining of the Danube, on April 16.