Dr. Seamus McGuinness:

I think some parts of the subvention debate are really not that controversial. I do not think many people would argue that the North's share of the cost of running embassy services and of defence spending would be maintained after reunification. Pensions become more of an issue because the UK model for pensions and national insurance is to fund current pensions, as opposed to people's future pensions. It does not actually legally equip anybody with a guaranteed right to a pension in the future. No one paying national insurance now who is not in receipt of a pension is legally guaranteed a pension in the future. That is the key issue here. I think this issue will have to be negotiated. It could be an issue on which a future British Government could completely renege. The possibility exists that they might take no liability for these pensions. The difference here is that there are existing treaty arrangements between the EU and the UK that were re-ratified after Brexit. Professor Mike Tomlinson has talked about this in his paper "Social Security in a United Ireland" in the journalIrish Studies in International Affairs. Those reciprocal rights mean that people's national insurance-type contributions made in both states are mutually recognised. A person can earn contributions in the UK and claim a pension in the EU and vice versa. This is an important aspect that will inform any negotiations on the issue. Professor John Doyle talks about existing custom and practice extensively in his paper. He gives multiple examples of people who have accrued national insurance contributions in the UK labour market and are subsequently paid in other jurisdictions - Spain, Dublin and elsewhere.

Coming back to the subvention debate and the issue around the North's share of running embassy services and military defence spending, we can forget the argument that those would carry on after reunification. The pensions issue is potentially more of a grey area. The Scottish Government is putting this back on the table in terms of its argument for a second independence referendum even though it seemed to be resolved before 2014. The evidence of the treaty obligations and custom and practice would suggest that those pensions, or at least a large share of them, would not remain a liability for the Irish Exchequer following on from any poll opting for reunification.