The Asbestos strike began 14 February 1949 and for the next 4 months paralyzed major asbestos mines in Québec, the most important of which were American-owned. From the start, this strike of 5000 workers affiliated with the CCCL (later Confederation of National Trade Unions) presented a challenge to the entire union movement, to the anglophone management in Québec, the province's political system and the Roman Catholic Church, and disrupted their former relationships. It began illegally, and thus broke with the CCCL's long tradition of co-operation with management. The asbestos fight also produced unprecedented inter-union solidarity.
Unions had previously formed a common front to battle an anti-union bill of the Union National government, and now the CCCL, the Fédération provinciale du travail du Québec (FPTQ, later part of QFL) and unions affiliated with the CCL and CIO organized strike-support meetings throughout Québec. The church also backed the strikers. This put the bishop's office in direct conflict with Premier Maurice Duplessis, whose police, based in mining-company offices, were in conflict with the strikers. The strike became a historical and political event of symbolic import that introduced Québec to an era of embittered labour conflict and presaged the Quiet Revolution.