The Minister of Supply in the British Government was in charge of the 1939–1959 Ministry of Supply, which was responsible for co-ordinating the supply of equipment to the armed forces. The position was campaigned for by many sceptics of the foreign policy of the National Government in the 1930s before ultimately being created in 1939.
During World War II there was a separate Ministry of Aircraft Production; the first minister Beaverbrook later became Minister of Supply. When W. A. Robotham was Chief Engineer of Tank Design in the Ministry of Supply, he demanded sound manganese steel castings for tank tracks, as a broken track could be a death warrant for the crew. Beaverbrook accused him of holding up production, and took a poor view of Robotham's observation "that they had enough unreliable tanks to last us the rest of the war!". In July 1941, 25% of British tanks were immobilised from mechanical failure, although there was no enemy action in the theatres of war.
The Ministry of Aircraft Production was amalgamated into the Ministry of Supply in July 1945.
In governments shortly after the war, the Ministry became increasingly unpopular with economy-minded Conservatives, who objected to it as a redundant middle-man. This point of view was shared by Reginald Maudling, who served as the Minister under Anthony Eden and refused to continue in office under Harold Macmillan, who had served in a junior role in the Ministry and believed in it, but agreed to wind it up in 1959.