IMHO, it would have to be just about THE most annoying thing you hear on the line. Pretentious Pommy (or pseudo Pommie)... (insert whatever word you want).
I've used the "XXX, call THE Frankfurt on 118.5." myself on the odd occasion when sharing the frequency with a "thee-er", but it doesn't seem to get through to them what absolute tossers they sound to the rest of the world.