George McLeay joined the Liberal Union and was elected to the Australian senate in 1934 where he led the Senate from 1938 to 1941.
At twenty McLeay joined the Liberal Union and in 1922 ran unsuccessfully for election for the seat of Adelaide in the House of Representatives. In the 1934 elections, he was elected to the Australian Senate. He was leader of the government in the Senate from November 1938 to October 1941 and Vice-President of the Executive Council from November 1938 to March 1940 and from October 1940 to October 1941. 
