At a time when immigration from the Global South has intensified in Europe, European countries are faced with the challenge to regulate their labour markets in a way that is the most likely to combine two key, and potentially contradictory, objectives: first integrating immigrants once they have reached Europe, second preserving the protection of European workers in terms of living standards and against risks and abuses. This research aims at contributing to solving this European challenge by providing a historical account and a historical comparison between key national cases in Europe of the opposition that has so far emerged between these two key objectives. To what extent has so far the opposition between the integration of immigrants from the Global South and the protection of European workers’ wages and working conditions contributed to shaping labour market regulation in key European countries? How have national cases differed regarding the magnitude of this opposition and regarding the options to solve it? My research objectives aim at completing the state-of-the-art in three ways: 1. Assessing the role of the opposition between global immigrants’ integration and European workers’ protection during major labour crises in key European countries; 2. Determining the extent to which unions, governments, and international institutions’ strategies aiming at addressing this opposition have impacted labour market regulation and immigration policies in Europe; 3. Evaluating the outcomes of these strategies in terms of global immigrants’ integration and European workers’ protection and their consequences. I will resort to the historical, archive-based, method of research and will focus on selected British, French, German, Italian, and Spanish documents, and on international sources.