While the implementation of English-medium instruction (EMI) in many elite universities is established as common sense, it is fraught with challenges and contradictions. In post-colonial multilingual contexts such as Hong Kong, we argue that EMI is sustained by neoliberal coloniality, whereby its status as an enduring legacy of the hegemonic colonial order is maintained by contemporary neoliberal imperatives. From a stancetaking perspective we examine how members of the public take up stances on EMI on an online forum, in response to an initial thread openly criticising its use on a social work programme at a Hong Kong university. Our analysis of 480 posts shows a range of stances with regard to three recurrent themes, namely practicality, flexibility and fairness. The findings indicate that EMI attracted strong affective rejection from some due to perceived impracticality and inflexibility in its implementation, as well as issues of inclusion in relation to students’ different linguistic repertoires. Conversely, they also reveal deeply entrenched ideologies supporting the use of EMI, most notably for its purported practicality and promised benefits. We conclude by reflecting on the value of stancetaking in understanding ideology and the specific ideological and practical implications of EMI in Hong Kong.