There is a growing expectation that Britain will trigger Article 16, a clause that allows for unilateral action if the Northern Irish Protocol, governing post-Brexit trade with the EU, is deemed to be having a negative impact. On Wednesday Ireland’s prime minister Micheál Martin heightened concerns that this was almost a racing certainty after his bluntest warning yet to the U.K. that such a move would be reckless, irresponsible, and have far-reaching consequences. Article 16 is a clause in the Northern Ireland protocol, one of the key elements in the withdrawal agreement, which legally cemented the U.K’s departure from the EU in January 2020. It allows either side to take steps if the protocol leads to serious economic, societal or environmental difficulties that are liable to persist, or to diversion of trade. The U.K. would have to prove that the protocol has given rise to serious economic, societal, or environmental difficulties. Brexit Minister David Frost has repeatedly said the conditions to trigger it are met because of the obstruction to trade flow between Britain and Northern Ireland. Although invoking Article 16 would not have a huge impact on the ground, the process triggers both sides to go into talks to resolve the dispute. The fear is that the U.K. will go farther and use the breakdown of talks to drive through domestic legislation to dump the role of the European court of justice in the arbitration process. Frost doesn’t have the last word; the decision on Article 16 would ultimately be that of British Prime Minister Boris Johnson.