[2] After World War II, membership of the Communist Party of Australia had peaked at around 20,000 and Fred Paterson had won the seat of Bowen in the 1944 Queensland state election.

Following the attempted nationalisation of the Australian Banks in 1948, Opposition Leader Robert Menzies became concerned that communist ideas were infiltrating the Labor Party.

[3] In the 1949 general election, the newly formed Liberal Party campaigned on a strongly anti-communist, anti-interventionist platform, which targeted the Labor government's attempt to nationalise banking in Australia, as well as what Menzies considered to be a growing communist threat in the wake of World War II.

Bargaining quickly broke down between the unions and government and on 1 August, Prime Minister Chifley sent in troops from the Australian Armed Forces to run the mines until the dispute was resolved.

[6] He accused the Labor Party of having communist leanings, citing as proof its banking legislation and regulation in other areas of the economy.

[9] In his speech introducing the Bill, PM Menzies read out the names of 53 members of the Communist Party of Australia, referring to them as a "traitorous minority" which threatened the security of the nation.

[11] These reservations were especially strong after Menzies admitted that the names of Communist Party members which had been read out on the House floor contained errors.

[13] The Commonwealth claimed that the Act was valid under this power because communists presented a real threat to Australian security, as revolution was a central theme of marxism.

A referendum was called on 23 August 1951, which sought to insert a clause into the constitution that empowered the Federal Parliament make laws in reference to communism and communists.

[15] Some Liberal party members and non-affiliated conservatives also supported the No campaign, which undermined Menzies efforts to convince the public that this was a necessary measure.

[16] The reason behind the Gallup support plummeting for Yes has been estimated to have been especially middle class Liberal voters slipping away from the Coalition position, whereas Labor kept their ranks better.

Reflecting on the outcome, Menzies remarked "to get an affirmative vote from the Australian people on a referendum proposal is one of the labours of Hercules".