The Northern Ireland Protocol has been lambasted as a “stick for the EU to beat the UK with” after Brexit.
It was negotiated at the 11th hour as a solution to one of the biggest sticking points in talks – the Irish border.
Under previous proposals there were rows over the functioning of the sole land border between the EU and UK, which is on the island of Ireland.
There was fierce opposition to a return to a militarised border in Ireland, and instead it was agreed that Northern Ireland would effectively remain in the single market for goods.
This means EU customs rules are applied at Northern Ireland’s ports and airports, even though the region is still part of the UK customs territory.
Article 16 of the protocol gives the EU or the UK the ability to unilaterally suspend aspects of its operation if either side considers that aspect is causing “economic, societal or environmental difficulties”.
It is only supposed to be triggered in the face of “serious” problems, and if one side triggers Article 16, the other side can take rebalancing action in response.
The protocol is regarded with hostility by unionists as a border down the Irish Sea, and some DUP MPs have called for Article 16 to be triggered over delays faced by hauliers transporting goods from Great Britain to Northern Ireland.
There is also fury at claims that Brexit red tape could hinder the movement of military equipment within the UK.
But antagonism reached a new level on Friday night when the EU moved to use the protocol to stop the unimpeded flow of vaccines from the bloc into Northern Ireland.
It was part of the EU’s efforts to place controls on the export of Covid vaccines amid its row with AstraZeneca over its supply contract.
The protocol theoretically presents a back door for exporters to circumvent those controls and move vaccines into Great Britain unfettered, because trade from the EU into Northern Ireland is unrestricted under the protocol, as is trade from the region into Great Britain.
Triggering Article 16 on the movement of the vaccines would have closed that back door.
The DUP’s Westminster leader Sir Jeffrey Donaldson told Times Radio: “That the EU was going to use the Northern Ireland Protocol as the very instrument to create a medicines border on the island of Ireland, to create a border between the Republic of Ireland and Northern Ireland for the very thing that people are looking for most at the moment – this coronavirus vaccine – just left me feeling absolutely incredulous.
“I’m glad they backed down but I’m afraid the genie is out of the bottle and that genie is that the EU clearly sees the Northern Ireland Protocol as a stick to beat the UK with.
“They did it yesterday, they will do it again. That is why we have said to the Prime Minister this protocol is harming the integrity of the UK single market. It is harming the Northern Ireland economy.”
Sir Jeffrey said whoever authorised the EU decision on Friday “should examine their own position”.
“It was an incredible decision for the EU to make,” he said.