By the people, of the people and for the people
The 1916 Proclamation states ". . . we declare the right of the people of Ireland to the ownership of Ireland, and to the unfettered control of Irish destinies, to be sovereign and indefeasible . . ." In other words, the people have and always will have, absolute authority here, no mention of either Fine Gael or the troika.
In 1937 the Constitution of Ireland was enacted and once again the key declaration of the 1916 Proclamation remains intact. Article 6.1 unequivocally states ". . . all powers of government, legislative, executive and judicial derive, under God, from the people, whose right it is to designate the rulers of the State and, in the final appeal, to decide all questions of national policy . . ." (my emphasis) This Constitution is still in force today.
So the answer seems clear enough. The 'people' own this country and have the right to decide what happens to it.