A UK analogue of the Xerox / Kleenex genericized trademark would have to be 'hoover', which has long meant simply 'vacuum cleaner, of any sort'.
(As an aside, the legal requirement to enforce trademark usage does more to damn the image of lawyers than anything else they do. So, to pick an example completely out of the air, I use the term 'google' in a column to indicate the act of searching the web, a use well-established for over five years now -- I know people who know the verb 'to google' but do *not* realise that you can also say 'to search the web'! -- and get a snotty letter from a lawyer.
Now what is the point of sending this letter at all? The only reason I could possibly have to do as the lawyer says and stop using the word to mean 'to search the web' would be in order to be nice to someone. Now being nice to someone is normal, but it is less normal to be nice to someone who's just sent me a pointless threatening letter complaining about a normal part of English language formation. IMO anyone who does it and is not actually selling something intended to confuse the public is a craven fool. And it's not even the poor lawyer's fault: [s]he's obliged to send this useless and unpleasant missive.)