My noble friend is absolutely right: it was a huge development, and of course all this was voted on in a referendum, north and south. In both Northern Ireland and in the Republic of Ireland, there were big majorities for precisely that.
But Brexit does affect where we are in Ireland and affects the principles of the Good Friday agreement to a certain extent. In the first place, Ireland, of all the 27 countries left in the European Union when we have departed, will be the most affected by Brexit; of that there is no doubt. It also means that some unionists in Northern Ireland—not all—now believe that exiting the European Union will in some way reinforce their Britishness. Some nationalists and republicans—not all—believe that Brexit will bring a united Ireland closer. None of that helps because at the end of the day the agreement was about an agreed island.
The noble Lord, Lord Hay, talked about the need for balance in all this. He was absolutely right: that balance can be upset by what is happening as a result of the debate on Brexit—not necessarily Brexit itself, but the debate on it. The purpose of the amendment before us is to enshrine the principles of the Good Friday agreement in the Bill.