Outright hostility is very unlikely, I think in the 10 years I have been here I only had one person who did not like I was a Brit, and it was only a minimal situation that I handled. Most people don't care about asking where you are from if they notice you are from another country. Expect to be defined entirely by the sterotype of being British, and if you outwardly advertise it (the England shirt), you may find the problems you would be looking for.
