This paper analyzes td-deletion, the process whereby coronal stops /t, d/ are deleted after a consonant at the end of the word e.g. best, kept, missed, in the speech of 93 speakers from Manchester, stratified for age, social class, gender and ethnicity. Prior studies of British English have not found the morphological effect—more deletion in monomorphemic mist than past-tense missed—commonly observed in American English. We find this effect in Manchester and provide evidence that the rise of glottal stop replacement in post-sonorant position in British English (e.g., halt, aunt) may be responsible for the reduction in the strength of this effect in British varieties. Glottalling blocks deletion, and because the vast majority of post-sonorant tokens are monomorphemic, the higher rates of monomorpheme glottalling dampens the typical effect of deletion in this context. These findings indicate organisation at a higher level of the grammar, whilst also showing overlaid effects of factors such as style and word frequency.