30 These teachings were issued indeed most opportunely. For at that time in many nations those at the helm of State, plainly imbued with Liberalism, were showing little favor to workers' associations of this type; nay, rather they openly opposed them, and while going out of their way to recognize similar organizations of other classes and show favor to them, they were with criminal injustice denying the natural right to form associations to those who needed it most to defend themselves from ill treatment at the hands of the powerful. There were even some Catholics who looked askance at the efforts of workers to form associations of this type as if they smacked of a socialistic or revolutionary spirit.
Source: Quadragesimo Anno (Vatican.va)