Northern Ireland's Prime Minister Michelle O'Neill and her party leader Mary Lou McDonald are planning a referendum on the reunification of the island before 2030. Sinn Fein achieved strong results in recent elections in both the Republic of Ireland and Northern Ireland.

Large parts of Irish society, which is predominantly Catholic, have been rebelling against the British crown for a long time. This led to Irish independence in 1921, while Northern Ireland remained part of the United Kingdom. Decades of tension followed, culminating in the violent conflict in Northern Ireland between the 1960s and 1990s.