The two major political parties in Ireland, Fianna Fail and Fine Gael, split in 1922 because Fianna Fail considered the Treaty that Ireland made with Britain didn't go far enough in terms of granting sovereignty back to Ireland. In 1921, the President of Ireland and future leader of Fianna Fail until 1959, Eamonn De Valera, made the following speech :
PRESIDENT DE VALERA: We definitely understood when we used the word plenipotentiaries. One of the Deputies of South Dublin asked me about the word and I said we understood it means they have full power to negotiate and to take responsibility for negotiating and signing. The word really meant the power of negotiating. They had their own responsibility for negotiating and signing. There is no treaty in recent times that is not brought to the main assembly for ratification or rejection. The plenipotentiaries have full power to negotiate and sign, they have not full powers to sign for the nation. I hold ratification is absolutely impossible for this Assembly. This Assembly cannot ratify a Treaty which takes away from the Irish people the sovereignty of the Irish people.
Almost one hundred years later, the current leader of Fianna Fail, Michael Martin, made the following speech :
Let there be no doubt about where Ireland stands. We want nothing to do with a backward-looking idea of sovereignty.
He went on to say, presumably aiming for some kind of statesman like ideal :
"We remain absolutely committed to the ideals of the European Union."We see the union for what it is - the most successful international organisation in world history."The union is flawed, but its successes are undeniable."It is hard to think of any EU successes that relate to Ireland. It was the EU who forced Ireland to pay billions of euros to unsecured bondholders. The EU might be successful for some, for corporatism and Statists and for Germany who benefit from the cheap currency, but for small nations like Ireland we are easily nudged aside. That's why Iceland has remained outside of the EU. Hoping that Ireland will somehow be treated nicely by the EU in the Brexit negotiations is not backed up by past experience.
It was Ireland's sovereign status which allowed De Valera maintain Irish neutrality throughout World War II, a success which helped make Fianna Fail the most popular party for generations afterwards. Now that they want to discard sovereignty (or outsource it to Brussels), Ireland can no longer remain neutral under Fianna Fail. You can't have neutrality without sovereignty.
Although I doubt it was the original intention, Fianna Fail have in effect, fought for Irish sovereignty, not for the right of the Irish people to have sovereignty but for the right to throw it away to someone else.