I am starting a new job in a couple of weeks in a very British (I presume) environment, i.e. civil service. I am an EU immigrant with unusual name. In my private life I've chosen to be called by a nickname- similar to my own but a British sounding name, which now my partner and majority of my friends use.
I know that I'll have to stick to my official name in documents etc, but would it be unreasonable to ask my colleagues to call me by my self imposed nickname?
Think of something like Malgorzata - to Maggie (I am not Polish by the way so it is just an example)