ABSTRACT Formulaic expressions/prefabricated chunks are established as crucial in fluent speech production in psycholinguistics and language acquisition/learning yet have been largely underexplored in interpreting studies, barring a few experimental studies. Formulaic expressions are particularly underexplored from a discursive perspective in interpreting, that is, how interpreters might employ formulaic expressions for discursive mediation. Drawing on 20 years of China’s political press conferences data, this study conducts a corpus-driven critical discourse analysis to explore the ideological/discursive properties of the linguistic category using the N-Gram function. The findings reveal that the interpreters’ formulaic language use manifests at multiple levels: Instead of being seemingly routine and innocuous, formulaic expressions used in interpreting can be ideologically salient in (re)constructing versions of truth, fact, and reality, discursively further strengthening China’s stance in the global lingua franca English. Contextualised bilingual examples are provided to demonstrate interpreters’ mediation. This interdisciplinary study contributes to current understanding of government interpreters’ agency in a changing sociocultural and geopolitical context.