Help me identify a uniform.

[DrinkFeckArseGirls]

Dark(ish) rich blue short sleeve shirt with shoulder badge (??) - gold crest with “C” underneath. Seems to be an everyday uniform, not for a special occasion.

Bump. Was on the receiving end of road rage earlier this evening and that prick had the shirt as above on.
SW London if that helps to narrow? Though Royal Navy or Fire Brigade as they’re relatively near by but can’t really pinpoint an exact shirt with golden crest on the shoulder.
Any Google searches give inane answers