In March 1940, Fadden was named a minister without portfolio in the government of Robert Menzies, who led the United Australia Party in a coalition with the Country Party. A few months later, following the deaths of three senior ministers in an air crash, he took over as Minister for Air and Minister for Civil Aviation. In October 1940, Fadden was elected acting leader of the Country Party as a compromise candidate, following a deadlocked leadership vote between Earle Page and John McEwen. He became the de facto deputy prime minister and was promoted by Menzies to treasurer.
In March 1940, Fadden was named a minister without portfolio in the government of Robert Menzies who led the United Australia Party in a coalition with the Country Party. A few months later, following the deaths of three senior ministers in an air crash, he took over as Minister for Air and Minister for Civil Aviation. In October 1940 Fadden was elected acting leader of the Country Party as a compromise candidate, following a deadlocked leadership vote between Earle Page and John McEwen. He became the de facto deputy prime minister and was promoted by Menzies to treasurer.