counties have Irish Catholic majorities and majorities voting for Irish nationalist parties, and Catholics have become the plurality in Northern Ireland as of 2021. The religious denominations of the citizens of Northern Ireland are only a guide to likely political preferences, as there are both Protestants who favour a united Ireland, and Catholics who support the union. Surveys identify a significant number of Catholics who favour the continuation of the union without identifying themselves as Unionists or British. Legal basis Article 3.1 of the Constitution of Ireland "recognises that a united Ireland shall be brought about only by peaceful means with the consent of a majority of the people, democratically expressed, in both jurisdictions in the island". This provision was introduced in 1999 after implementation of the Good Friday Agreement, as part of replacing the old Articles 2 and 3, which had laid a direct claim to the whole island as the national territory. The Northern Ireland Act 1998, a statute of the Parliament of the United Kingdom, provides that Northern Ireland will remain within the United Kingdom unless a majority of the people of Northern Ireland vote to form part of a united Ireland. It specifies that the Secretary of State for Northern Ireland "shall exercise the power [to hold a referendum] if at any time it appears likely to him that a majority of those voting would express a wish that Northern Ireland should cease to be part of the United Kingdom and form part of a united Ireland". Such referendums may not take place within seven years of each other. The Northern Ireland Act 1998 supersedes previous similar legislative provisions. The Northern Ireland Constitution Act 1973 also provided that Northern Ireland remained part of the United Kingdom unless a majority voted otherwise in a referendum, while under the Ireland Act 1949 the consent of the Parliament of Northern Ireland was needed for a united Ireland. In 1985, the Anglo-Irish Agreement affirmed that any change in the status of Northern Ireland would only come about with the consent of a majority of the people of Northern Ireland. History Home Rule, resistance and the Easter Rising The Kingdom of Ireland as a whole had become part of the United Kingdom of Great Britain and Ireland under the Acts of Union 1800. From the 1870s, support for some form of an elected parliament in Dublin grew. In 1870, Isaac Butt,