This article examines the contrasting attitudes of Taiwanese and South Korean labour unions towards migrant workers, focusing on the roles of collective identities and party-union linkages. Facing unskilled labour shortages, both Taiwan and South Korea opened their labour markets to foreign workers in the 1990s. This influx of transnational labour, however, led to a range of human rights issues. In response, civil society groups in both countries launched advocacy movements to address these challenges. Interestingly, Taiwanese labour unions have been less supportive of migrant workers, while their South Korean counterparts have actively engaged in social movements, displaying a strong sense of solidarity and collective identity. To explain this discrepancy, the article analyses how unions' collective identities and party-union linkages have shaped the divergence in unions' attitudes towards migrant workers. In Taiwan, ethnic divisions among workers and strong party-union linkages have contributed to unions' exclusionary stand, whereas in South Korea, a legacy of militant activism and the absence of institutionalised political ties have fostered an inclusive approach. These structural differences explain why Korean unions have mobilised alongside migrant workers, while Taiwanese unions have remained largely resistant to their inclusion.
