Question: Irish unionists use the two nations theory as a basis for opposing a movement that agitated for self-government that was the dominant political movement of Irish nationalism until when? 
Sentence (from "Protestant Irish nationalists"): Protestants have played a rather large role in the development of Irish nationalism since the eighteenth century, despite most Irish nationalists historically being from the Irish Catholic majority, as well as most Irish Protestants usually tending toward unionism in Ireland.
Relevant evidence: No