This dissertation examines how the transition from internal combustion engine vehicles (ICEVs) to battery electric vehicles (BEVs) is reshaping employment relations in South Korea’s auto industry, with particular attention to labor market dualism and the evolving agency of precarious workers. As Hyundai Motor Group (HMG) and its supplier network restructure production systems to accommodate electrification, longstanding segmentation between core and peripheral workers has not only persisted but deepened—raising critical questions about the distributive consequences of green industrial transformation and the prospects for a just transition. Drawing on qualitative fieldwork—including interviews with workers, union representatives, corporate executives, and managers, as well as field observations and analysis of collective agreements, union documents, and policy materials—the dissertation investigates how industrial relations institutions and collective actors mediate the effects of restructuring on job quality and worker power.Chapter 1 analyzes how the shift to BEV production has reinforced labor market dualism, particularly between regular workers in core OEM plants and precariously employed subcontract workers in supplier firms. It highlights how fragmented bargaining institutions and limited coordination across the supply chain constrain unions’ capacity to pursue inclusive strategies. Chapter 2 turns to the internal politics of enterprise unionism, showing how contested authority between union leadership and shopfloor delegates shapes responses to outsourcing and limits efforts to represent nonstandard workers. Chapter 3 introduces the concept of ambidextrous solidarity to theorize how grassroots labor networks among subcontracted workers sustain collective power by combining decentralized organizing with the institutional leverage of established unions. It further identifies the organizational conditions under which such hybrid strategies are negotiated and maintained over time. Together, these chapters offer a multi-level analysis of how industrial restructuring interacts with institutional configurations, intra-union dynamics, and emergent forms of worker agency. By situating the Korean case within comparative debates on just transition and labor market segmentation—including cases from Germany, the United States, and Canada—this dissertation contributes to employment relations scholarship by identifying the conditions under which precarious workers can not only resist exclusion but actively shape more equitable outcomes. In doing so, it advances theoretical understandings of worker power in fissured production regimes and highlights ambidextrous solidarity as a strategic response to the fragmentation of labor representation and the deepening of employment precarity.