Professor Colin Harvey:

There are two aspects to that. First, the question of leaving effectively unenforceable instruments such as this will have to be thought about in the discussions to come. If - and that is an "if" - there is beyond the withdrawal agreement some kind of new British-Irish agreement, thought will have to be given to how it will be implemented and enforced, including judicially. Second, Ireland has gone to the European Court of Human Rights regarding the UK and gone back again, as we know, regarding a situation in Northern Ireland. I say this because we are in a serious situation whereby one gets to a point at which if one of the participants in a peace process is paying continual lip service to its core principles while not respecting them and there is nothing one can do about that, that is a big problem. There are many other contributors to the problems we face in Northern Ireland but that is one of the major issues. Much more thought needs to be given by the Irish Government in the weeks and months ahead in these negotiations. I live in Belfast. I do not want to be stuck in 20 years' time with political principles agreed as part of this discussion to find out 15 years down the road that they are paper principles and are meaningless in practice. It is for the Irish Government and for me as an Irish citizen living in Belfast to make sure that will not be the case in the future.

I have spoken too much but, to repeat the point about Operation Gull and other matters, I genuinely think that on this island we need to start a new conversation about where we want to go on some of these issues, including immigration, asylum and refugee policy. The Westminster Government is going, in my view, to a bad place in respect of some of these issues and we must bring our mind to these questions. For example, does the Westminster approach to immigration and asylum suit us in Northern Ireland? It is not a devolved issue down the road. It is the same in Scotland. We need to think of more constitutionally pluralist ways across these islands. Migration is one such issue, and we need to see human rights and equality. Racial profiling is appalling, given some of our values and principles, and we should not be involved in arrangements that are facilitating it.

Many people thought a new constitutional conversation was happening in the UK, in Scotland as much as Northern Ireland. A shocking thing for many people involved in constitutional law was that they thought the UK was becoming a more constitutionally pluralist place, a place where the Good Friday Agreement principles were respected in law but unfortunately, in the past few years that has proved to be wrong.