On June 23rd 2016 the UK had a referendum on membership of the EU, and they voted to leave, but a majority of the people in the North of Ireland voted to remain in the EU and when Brexit happens they will be dragged out of the EU against their wishes and made to suffer the damage of a mess and a problem which was created in England, and as well as that with Ireland being divided it will mean the South will be in the EU and not the UK, and the North will be outside the EU and inside the UK in that case border checkpoints may be installed which goes against the Good Friday Agreement, an international peace treaty signed in 1998 and which the people on the island of Ireland voted in favour of in a referendum.

So in this case, a referendum on the constitutional position needs to be held!!