Ireland?
This has nothing to do with the EU.
The Brexit slow up, created by Theresa May was over the Northern Ireland (being part of the UK) being withdrawn, affecting the companies set up in Northern Ireland, and the tariffs that would commence with anything coming in from the EU into the now withdrawn non-EU member UK/Northern Ireland.Coming in via Republic of Ireland, or by sea from... anywhere. The “invested” foreign sited companies in N. Ireland. The Tory (conservatives) say— tough crap, and this would remove the political/money/EU pressure put on N. Ireland by the Irish Republic (which would remain as part of the EU and thus the N. Ireland trade with Repub of Ireland greatly reduced due to the tariffs).
Article here: https://www.rte.ie/news/analysis-and-comment/2019/0614/1055418-double-whammy-a-no-deal-brexit-and-northern-ireland/
might also add:
Adding to the tension, is the very long memory the UK have about how “UN-neutral” Ireland was during WWII- german agents, and much else through Ireland into N. Ireland and there to London. The story of Normandy invasion deception had to be protected from “irish eyes”/german spies. There is also a lingering memory of the treatment of some 5000 Irish Army members who shed their uniforms to join the British Army & fight Hitler and how they and their descendants have been treated since the war.
Quote......” 5,000 Irish soldiers who deserted their own neutral army to join the war against fascism and who were brutally punished on their return home as a result.”
https://www.bbc.com/news/uk-16287211