Since their appearance in the mid-1990s, Chinese labour NGOs have mostly focused on three kinds of activities: establishing workers' centres; carrying out outreach programs on labour rights; and conducting social surveys and policy advocacy. Some scholars have strongly criticised this approach, considering it excessively unbalanced towards an individualistic and narrowly legalistic view of labour rights and thus in line with the political agenda of the Party-state. Still, in the past few years, as labour conflict intensified, a handful of labour NGOs have moved forward to adopt a more militant strategy focussed on collective bargaining and direct intervention into worker collective struggles. Based on dozens of interviews with labour activists and workers and detailed analysis of two case studies of NGO-fostered collective labour mobilisation in Southern China in 2014-2015, this paper will outline the personal and political reasons that motivated these organisations to move beyond a narrow legalistic approach and turn towards collective struggles. It will also describe the strategies that Chinese labour activists have adopted in dealing with collective cases. We will conclude by examining the main challenges that labour activists in China have to face when dealing with labour unrest and by questioning the sustainability and feasibility of this new approach in the current political climate.