Reunification will ask taxing questions of our republic 

The Border poll will not be the sole constitutional hurdle that will need to be cleared if Irish unity is to be agreed

A billboard presents a solution to the problems that have emerged from Brexit. Photo: Paul Faith/AFP via Getty.

Colm McCarthy

Brexit and the fallout over the Northern Ireland protocol have reminded everyone  the Good Friday Agreement promises, or threatens, a process of constitutional change with destabilising potential.