There's a minority of people in England whose racism takes in the Irish, and that's actually got a good side, because they tend to be the same kind of creeps who are racist in other directions. There was an expression one time reflecting that - "toasted Irishman", meaning someone from an Afro-Caribbean background. Why I say it's got a good side is that it's probably a kind of protection for some people against slipping into those kinds of racism.

But antagonism towards Irish people is a minority sport in my experience, in the parts of the country I've lived in anyway. Ignorance about Ireland and Irish history, that's a different matter, but then most English people tend to be pretty ignorant about England and English history, and that's down to the education system rather than prejudice.