Lord Frost, who has travelled to Northern Ireland today to meet with political parties and businesses, has told BBC Radio Ulster that while he would “very much hope” to conclude the negotiations “Article 16 is a very real option for us.”

The Protocol was implemented to prevent a hard border between Northern Ireland and the Republic of Ireland in the wake of Brexit by keeping Northern Ireland in the EU’s single market for goods. It has been heavily criticised by unionist groups for allegedly undermining the union between Northern Ireland and the rest of the UK, which remains outside the EU customs union.

The triggering of Article 16 would allow parts of the protocol to be unilaterally suspended. The Article is intended to be a “safeguard” if either the EU or UK believe that Protocol is leading to “serious” practical problems or a diversion of trade — “economic, societal or environmental difficulties”. There is no specific guidance on what qualifies as a “serious” difficulty.