Australian Labor Party split of 1955

The Australian Labor Party split of 1955 was a split within the Australian Labor Party along ethnocultural lines and about the position towards communism. Key players in the split were the federal opposition leader H. V. "Doc" Evatt and B. A. Santamaria, the dominant force behind the "Catholic Social Studies Movement" or "the Movement".

I have witnessed three disastrous splits in the Australian Labor Party during the past fifty-six years. ... The first split occurred in 1916 over conscription in World War I; the second in 1931 over the Premiers' Plan for economic recovery in the Great Depression; and the third in 1955 over alleged communist infiltration of the trade union movement. The last was the worst of the three, because the party has not yet healed the wounds that resulted from it.

Arthur Calwell[1]

Evatt denounced the influence of Santamaria's Movement on 5 October 1954, about 4 months after the 1954 federal election. The Victorian ALP state executive was officially dissolved, but both factions sent delegates to the 1955 Labor Party conference in Hobart. Movement delegates were excluded from the conference. They withdrew from the Labor party, going on to form the Australian Labor Party (Anti-Communist) which in 1957 became the Democratic Labor Party. The split then moved from federal level to states, predominantly Victoria and Queensland.

Historians, journalists, and political scientists have observed that the split was not a single event but a process that occurred over the early 1950s in state and federal Labor parties. The conservative Catholic and staunchly anti-ALP Democratic Labor Party used Australia's full-preference instant-runoff voting system to direct its preferences to benefit the Coalition two-party-preferred vote and was successful until 1972 in preventing the election of an Australian Labor Party federal government.