Interestingly - after the United flight landed at BRU instead of FRA, by mistake, Brussels ATC would NOT answer if you did NOT say "Brussels Control" on first contact.. I'm not sure if that's changed recently - I can't remember when I last flew through Brussels airspace
Edited to add that if any Brits display poor R/T then that's really bad as all UK CAA qualifed pilots have to (ok - had to) do an R/T exam with some crusty old examiner sitting in a room next to you attached to a telephone playing ATC.. I've still got the old red license lurking around somewhere.. Forget ICAO 'let's play English language' nonsense.. This was the real thing