There is a very real pro-Monarchy, post-Empire resentment of anything not British among a large section of the British people. They might not say it out loud, but it's clear in the things they say.
I think that is untrue. This thread is the first time I've heard anyone mention Empire in connection with Brexit.
There is xenophobia but I think if you look closely you'll find that in most European countries as well. No doubt that instinct will now be directed at the British.
There is a very real pro-Monarchy, post-Empire resentment of anything not British among a large section of the British people. They might not say it out loud, but it's clear in the things they say.