The advent of platform work has led to deepened debate about the role of trade unions in our contemporary, segmented labour market. One of the crucial questions unions face is how to approach the protection, and organisation, of platform (“gig”) workers. The dilemma about whether to extend employment protection to more of those who work outside of the classical employment relationship can be solved in at least two ways: by changing labour legislation, and/or by extending the scope of collective agreements. This paper analyses two different approaches, from a common law and civil law perspective within the EU, and evaluates their efficacy. The common law perspective is analysed by looking at the case of Ireland, while from the civil law perspective the case of Slovenia is presented. In both countries, trade unions have been struggling to define strategies to approach the issue of the diversification of work relations. On the one hand, unions are wary of eroding the benefits of “employee” status, but on the other, in the context of membership decline, demonstrating relevance to increasing numbers of “non-standard” workers (including “gig workers”) is more important than ever. The paper assesses the union movements’ response in both countries to the “Uberisation” of work.