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 Director of Military Intelligence (DMI): concerning a query from the Prime Minister (PM) to the Chief of the Imperial General Staff (CIGS); this file also includes the following reports on North Africa: a German Air Force (GAF) air transport report about the Siwa oasis on July 23; and of GAF intentions on air transport for July 22-23.