[3] He became the first president of the Amalgamated Surface Workers' Union and the secretary of the Eastern Goldfields District Council of the Labor Party.
[1][4][5] Millington contested and won the inner metropolitan electorate of Leederville at the 1924 election, and was promoted to Cabinet as Minister for Agriculture in 1927.
[6] His Leederville electorate was divided into two in a redistribution in 1930, and Millington contested and won the new Mount Hawthorn seat.
He served, variously, as minister for education, police, industries, works, water supply, local government, town planning and main roads, under both Collier and his successor Willcock.
[7][8] He died at St John of God Subiaco Hospital in 1951, four days after being admitted for heart problems.