The learning of prestigious international languages becomes a process fraught with tensions in multilingual settings. The process of internationalisation in many universities has led to the spread of English-medium instruction (EMI), which tends to raise linguistic debates particularly in the case of bilingual institutions. However, and despite a few exceptions, there is scant research into the effect of EMI on the different bodies that make up the university community, especially in the case of teaching staff and administration personnel (as most studies focus on students). The participants in this study were 648 students, teachers and administration personnel who filled out a questionnaire. The analyses of the data revealed the existence of language tensions among the different languages in contact. Parallelisms and differences were found among the three different bodies, which led us to put forward a series of implications related to the implementation of EMI courses, as well as to multilingual language policies at university.