We would put it this way: the Republic is obliged, by the Belfast Agreement, to respect British identifications among the northern-born, in all scenarios, and to recognise the British citizenship rights of future northerners if the UK does.Currently, only Irish citizens can vote for the president, or in constitutional referendums. The situation is different for elections to Dáil Éireann, the European Parliament and local government.
They won’t wish accidentally to become Irish citizens simply because of seeking to vote in a presidential election or constitutional referendum .Advocates of a united Ireland may therefore opt for one of two feasible ways of accommodating British citizens, born in the North : The first option is less accommodating of British identifiers who do not wish to become Irish citizens under Irish unity.
Just over one-third of southerners agree with them, so passing the relevant constitutional amendment might be difficult.Unsurprisingly, responses in the North vary across religious background and national identity. Looking at party supporters across the island, Fianna Fáil voters are the least in favour of “British only” citizenship, and the most in favour of Irish-only citizenship.
British identifiers in Northern Ireland may react negatively to a future demand that they become Irish citizens.