Sir Jeffrey Donaldson: Post Brexit trade disruption breaches the Good Friday Agreement

He urged the Government to intervene to resolve the issues that have hindered the flow of food products from Great Britain to Northern Ireland since the end of the transition period.

Sir Jeffrey told BBC Radio 4’s Today programme: “The protocol (which governs the new arrangements) is damaging the Northern Ireland economy and if it damages the Northern Ireland economy it actually undermines the Good Friday agreement.

“And furthermore, that agreement makes clear that Northern Ireland will remain an integral part of the United Kingdom unless the people of Northern Ireland vote otherwise.

“Therefore this breaches a fundamental element of the Good Friday agreement by increasingly separating Northern Ireland from Great Britain in trading terms – our biggest trading partner, our biggest trading market, and that simply doesn’t help anyone in Northern Ireland.”

Boris Johnson has admitted there are “teething problems” in the post-Brexit trade relationship between Great Britain and Northern Ireland as industry experts warned there could be fresh shortages on supermarket shelves.

Yesterday retailers warned that shops in Northern Ireland could face further problems unless the EU is prepared to extend the “grace period” in the Brexit agreement.

British Retail Consortium director Andrew Opie said problems which had resulted in a shortage of some food products following the end of the Brexit transition period on December 31 had largely been overcome.

But he said there could be fresh difficulties in April when a series of exemptions on goods being moved to Northern Ireland from Great Britain comes to an end.

Mr Johnson told MPs on the Commons Liaison Committee: “The situation in Northern Ireland is that trade is flowing smoothly, as I understand it.

“And exporters are benefiting from the unfettered access between Great Britain and Northern Ireland.

“Yes, I am not going to deny down that there are teething problems, and there are issues that we need to sort out… but the deal has been of great, great assistance to our businesses in smoothing this.”

He said the Government would invoke Article 16 of the Northern Ireland Protocol – which allows it to unilaterally impose safeguards – if serious issues arise.

“What I can certainly guarantee is that if there are serious problems in… supplying supermarkets in Northern Ireland because of some piece of bureaucracy that’s misapplied, then we will simply exercise Article 16 of the protocol.

“It is absurd that there should be such difficulties.”

Earlier Mr Opie warned MPs that “if we do not find a workable solution for retailers in the next couple of months we do face significant disruption in Northern Ireland”.

He told the Commons Brexit Committee that supermarkets which exported to the Republic of Ireland had found the system was “unworkable” as far as their supply chains were concerned.

“That is why we need to think about Northern Ireland. We should not just be trying to apply the same processes that apply to the EU into Great Britain-Northern Ireland,” he said.

“Sending a lasagne from Great Britain to the Republic of Ireland is so complicated. You have to have authorisation going up through the chain, the vet at the end has to sign it off and he has to see all the authorisations.”