Weird, the information is out there and most manufacturers list ingredients about their products, why supermarket chains don’t list this stuff is a mystery, its the most important thing about the product. Currently I have to cross-reference everything with vegan sites like https://www.vegansociety.com/resources/lifestyle/shopping/lists-vegan-items-uk-supermarkets.

Lists of vegan items in UK supermarkets

Link: https://www.vegansociety.com/res

A guide to shopping for vegan products in UK supermarkets.