It is. Their history is one really long story of oppression from the English. A lot of Irish, and Welsh have been the hardest fighters for socialism because defeating Anglo-Saxon capitalism is the best hope of free themselves from the English, that's at least how James Connolly saw it.
A Scottish nationalist told me part of the reason he is a nationalist is because he feels England is a backward country and too 'conservative' (read: reactionary) for him. That and I guess, cultural differences he feels still.