Southeast Asia has received scant attention from socio-legal scholars, despite its rich repertoire of environmental legal action. Thus, I seek to partially address this lacuna by evaluating a subset of Malaysia’s environmental legal mobilisation. Specifically, I investigate localised legal responses to the (potential) threats to the environment posed by foreign-owned plants. Complicating the picture is the predominant ethnic Chinese profile of these communities in a country where ethnicity retains marked political salience. However, if Malaysian courts have been prone to executive interference, why and how does law still matter for minority ethnic communities in their struggle to attain environmental justice? How has the meaning-making process of these citizen activists shifted, if at all, through time? I argue that the logic driving grassroots environmental litigation is forged through three conditions: Malaysia’s post-colonial legacy of constitutional liberalism and ethnic divisions has privileged law as the prime dispute-processing mechanism, leading to the state’s contingent toleration of a relatively resilient activist-politician-lawyer alliance. The activist coalition would shape grassroots motivations for legal action, imprinting an activist tactical logic of garnering political legitimacy and publicity. Further, the precarious position of the ethnic Chinese in Malaysia’s body politic sharpens the protagonists’ natural desires for the legitimacy gifted through court action. Based on data from interviews with activists and documentary research, I utilise three case studies, each from a distinct historical period, to demonstrate how a liberalising political opportunity structure, instead of legal opportunity structure, better explains the growing confidence and willingness of citizen activists to litigate.