The United Kingdom unilaterally decided on Wednesday to extend the period during which British companies do not pay import duties on goods entering Northern Ireland until October 1.
Ireland and the European Union are not happy about this.
British Minister for Northern Ireland, Brandon Lewis, came up with a plan on Wednesday evening.
In it, he outlined some measures to make it easier for British supermarket companies that also have a store in Northern Ireland.
This is accompanied by a lot of extra administration.
Northern Ireland is no longer a member of the EU since Brexit, but it is part of the European customs union.
This means that the country must comply with European rules with regard to food safety, among other things.
And so taxes are also levied on goods entering the country.
Until now, the supermarkets were given some respite from the EU and those taxes did not have to be paid, but that was only temporary.
However, Lewis now decided to extend that period to October 1 without discussing this with the EU.
That went badly in Ireland.
Foreign Minister Simon Coveney calls the measure "extremely unhelpful in building the relationship of trust necessary for the implementation of the Irish protocol."
No border on the island of Ireland
He thereby refers to agreements around the border between Ireland and Northern Ireland.
Ireland is a member of the European Union, but Northern Ireland is part of the UK.
However, in 1998 it was agreed never to create a border on the Irish island.
This has led to quite a few tensions since Brexit and the British and European negotiators are now trying to resolve them.
Unilateral decisions will not advance those talks, Coveney says.
The EU is also disappointed.
"This is a violation of the provisions of the Irish protocol," said European Brexit negotiator Maros Sefcovic in a statement.
"It's also a clear departure from the constructive approach so far and it undermines the work on both sides."
Sefcovic said the EU will respond "appropriately" to the decision.