Although the group campaigned for the rights of workers and against what it saw as the excesses of capitalism, Santamaria came to see the Communist Party of Australia, which in the 1940s made great advances in the Australian trade union movement, as the main enemy.

In 1937 he was persuaded by Archbishop Daniel Mannix to join the National Secretariat of Catholic Action, a lay activist organisation.

In 1972 Arthur Calwell, a leading Catholic Labor politician, confirmed that Santamaria had "dodged" war service after Mannix had approached him to gain the exemption.

I want the country to know that these three men who have been pestering and opposing and demonstrating against the Australian Labor Party for the last 30 years were people who dodged military service'.

In October 1954, the Sydney Sun-Herald reported on a letter sent by the Victorian Minister for Lands, Robert W. Holt, to the federal secretary of the Australian Labor Party, a Mr J. Schmella, which the paper described as "probably as explosive, politically, as any document in Australia".

[12] Holt stated "My charge is that the Victorian branch is controlled and directed in the main by one group or section through Mr. B. Santamaria ... My criticism is not personal.

Holt spoke of events the previous year and described attending a meeting of Santamaria's National Catholic Rural Movement Convention, following which he was, as Minister of Lands, approached by Santamaria and Frank Scully, where he was asked to use his position to make Crown land available to "Italians with foreign capital".

He added that "subsequent events which happened during the selection ballot' had convinced him that the ALP's "Victorian branch is not free to implement Labor policy and connives with this method".

In Victoria, Dr Mannix strongly supported Santamaria, but in New South Wales, Norman Cardinal Gilroy, the first Australian-born Roman Catholic prelate, opposed him, favouring the traditional alliance between the Church and Labor.

"[15] Santamaria made this statement when he denied charges from the general secretary of the Australian Workers' Union (Mr T Dougherty) that the "No.

2-man in the NSW Labor Party" (J. Kane) and the "secretary of the Australian Rules Football Association of Queensland" (Mr Polgrain) were Santamaria's "top lieutenants in The Movement".

[15] Santamaria founded a new organisation no longer an organ of Catholic Action, the National Civic Council (NCC), and edited its newspaper, News Weekly, for many years.

Santamaria ran the NCC in a highly personal and (according to his critics) autocratic way, and in 1982 there was a serious split in the organisation, with most of the trade unionists leaving it.

[16] The Federated Clerks' Union and three others similarly aligned 'right-wing' unions – the Shop, Distributive and Allied Employees Association, the Federated Ironworkers' Association of Australia and the Amalgamated Society of Carpenters and Joiners – had their re-affiliation cases considered by a special Victorian ALP committee of ten which split on the decision 5 against 5 and had submitted separate reports to the State Conference.

The Federated Clerks' case, 'after a bitter and at times acrimonious 3 and a 1/2-hour debate', which was 'centred on alleged links' with Santamaria, the National Civic Council, and the Industrial Action Fund, was defeated at the State Conference by 289 votes to 189.

[16] It was noted in a news report of the time that all four were likely to appeal to the federal ALP executive and that they had the support of then Prime Minister Bob Hawke.

[22] Santamaria also opposed what he saw as liberal and non-traditional trends in the Catholic Church following the Second Vatican Council (which he had sought to attend as an independent observer), and founded a magazine through his Thomas More Centre, called AD 2000,[23] to argue for traditionalist views.

On his death Santamaria was praised by conservatives for his opposition to communism, but also by some on the left (such as veteran left-wing Labor ex-Cabinet Minister Clyde Cameron) and by social democrats (such as former Governor-General Bill Hayden) for his consistent critique of unrestricted capitalism.