Colm McCarthy’s belief that maintaining trade links with Northern Ireland should be made a poor second to the ‘Holy Grail’ of keeping friendly with ‘John Bull’ sets the whole Brexit debate into a much starker perspective.

Courtesy of his presentation to the recent MSD Animal Health conference, the UCD economist pointed out that the Republic of Ireland does 11 times’ more food-related business with Britain than it does with Northern Ireland.

And, on that basis, the priority must be to maintain the strongest possible trading links with the folks across the sheugh.

OK, in purely economic terms, he is probably right.

But I am not an economist. However, I was brought up to believe that everything must be done to harmonise relations on the island of Ireland. And, on that basis, McCarthy’s message really stuck in my craw. The other aspect to his presentation that annoyed me was its very narrow base.

He spoke only about the singular interactions between the Republic of Ireland and Northern Ireland, on the one hand, and the extent of the current trading links between the Republic and Britain on the other. He never mentioned the possibility of securing a Brexit deal that would allow for the ongoing maintenance of the current trading relations between the three regions.

The last four decades have seen a tremendous harmonisation of the food industry on the island of Ireland.

Last week’s confirmation by Dawn Meats that it is investing in Dunbia is the latest in a long line of cross-border investment decisions taken within the sector. Other recent examples of this nature include Lakeland’s acquisition of Fane Valley’s Dairy Division and the merger of Town of Monaghan and Ballyrashane Co-ops to form LacPatrick.

McCarthy’s thinking also seems to overlook the fact that any diminution of cross-border trade links will directly hit farmers’ pockets.

Currently, half the pigs reared in the Republic of Ireland are processed in Cookstown, Co. Tyrone. And, for the record, the trade links in the opposite direction are even stronger. For example, one-quarter of all the milk produced in Northern Ireland is now processed south of the border.

All of this begs the question: Why can’t we have a Brexit trade deal that maintains all of the trading patterns that currently exist between the Republic of Ireland, Northern Ireland and Britain?  It seems like the obvious solution. But if we don’t ask for this, we won’t get it.