The question of Northern Ireland's post-Brexit trading arrangements, better known as the EU/UK Trade and Cooperation Treaty, has the United Kingdom and the European Union on a collision course.
UK is demanding that the Northern Ireland Protocol be substantially reconsidered and rewritten. But the EU insists the terms of the protocol were bilaterally agreed and must remain.
On Tuesday UK's Brexit minister, David Frost, in a speech in Lisbon again threatened to ignore the protocol if the EU does not agree to new terms.
Frost said the protocol was the biggest source of mistrust between us and urged the EU not to make a serious historical error.
This Wednesday the European Commission is releasing its own proposals on possible amendments to the protocol.
EC vice-president Maros Sefcovic has made several trips to Northern Ireland with a view to making improvements to the protocol from the perspective of Northern Irish business people.
The proposals are expected to significantly ease rules around the movement of medicines and farm produce from Britain to Northern Ireland. However the dispute over the European Court of Justice jurisdiction regarding the post Brexit deal, which UK rejects, remains standing for the EC
Frost insisted that the protocol in its current form must go. The protocol is not working, he said. It has to change.
But the EU with the support from the Irish government has consistently pointed out that Prime Minister Boris Johnson fully agreed and signed the terms of the Northern Ireland protocol in 2019. During a now famous one-on-one meeting with Leo Varadkar, then the prime minister of Ireland, in October 2019, Johnson agreed to the various arrangements, including the ECJ's role, all of which were then officially enshrined in the Trade and Cooperation Agreement, which had the approval of the UK Parliament.
The purpose of the protocol is to avoid the return of borders to Ireland, an arrangement that is seen as vital to maintaining the 1998 Good Friday Agreement peace deal, which largely ended 30 years of bitter sectarian conflict on the island.
The focus now is on whether the United Kingdom will bring the protocol into official dispute by triggering Article 16, which provides for either side to institute unilateral safeguard measures if it believes there are serious economic, societal or environmental difficulties. In his Lisbon speech, Frost specifically mentioned Article 16 as an option that the United Kingdom was seriously considering.