Could you have an all island referendum? And what if the 6 counties failed to ratify your constitution? The article I read suggested that there would need to be two referendums in the south but the GFA specifies a single Yes/No referendum in the north. Which might be contentious if only people in the south had a say on the detail.It's possible. It would depend on the terms of reunification. If the 6 counties were to come in on the same terms as the existing 26 then there's already provisions in the constitution for that. If they were to have a devolved government in Belfast then that might require an all island referendum. The 6 counties would also need to ratify our constitution by referendum.