This paper delves into the concept of ‘enregisterment,’ which defines processes and practices linking linguistic repertoires with social meanings, by examining meta-linguistic commentary in newspapers. Focussing on ‘Multicultural London English (MLE),’ the study analyses 200 articles from major British newspapers (2006–2022) qualitatively and quantitatively. The research uncovers recurring linguistic shibboleths, indexically linked social meanings, and prevalent language ideologies concerning MLE and other London dialects. Results reveal a consistent emphasis on specific linguistic shibboleths repeated in articles. Indexical links for ‘MLE’ are constructed through evaluative comments, alarmist metaphors employing xenophobic immigration tropes, and loaded keywords. ‘Cockney’ and ‘Estuary English’ are portrayed more favourably and, together with ‘Received Pronunciation (RP)’, serve to stigmatise MLE. This study underscores the role of media discourse in shaping the enregisterment of dialects, contributing to social stratification and the ‘othering’ of certain linguistic varieties. •Multicultural London English (MLE) is ‘enregistered’ in English newspapers.•Enregisterment describes the process of linking social meanings to linguistic shibboleths, thus creating sociolinguistic indexes.•Enregisterment happens against a backdrop of language ideologies, which become apparent in newspaper discourse.•MLE is often evaluated negatively in newspapers due to conservative ideologies, also in left-leaning newspapers.•Other London dialects are used to ‘other’ MLE and receive a more benign treatment in print media.