The European Union will take legal action against the UK over its decision to extend the grace period on food controls between Britain and Northern Ireland, a move Brussels considers "a violation" of the Brexit trade agreement.
In a statement, European Commission Vice-President Maroš Šefčovič on Wednesday expressed his "strong concerns" about this "unilateral action" by the British government which, he said, "a clear departure from the constructive approach that has prevailed up until now".
"Following the UK government's statement today, Vice-President Šefčovič has expressed the EU's strong concerns over the UK's unilateral action, as this amounts to a violation of the relevant substantive provisions of the Protocol on Ireland/Northern Ireland and the good faith obligation under the Withdrawal Agreement," the statement said.
"This is the second time that the UK government is set to breach international law.
"This also constitutes a clear departure from the constructive approach that has prevailed up until now, thereby undermining both the work of the Joint Committee and the mutual trust necessary for solution-oriented cooperation".
Posting on Twitter, Šefčovič added that he would "be raising our strong concerns" with the UK's Lord David Frost, a Cabinet Office minister for Europe, Brexit and trade and former Brexit chief negotiator.
The British decision constitutes a "violation" of the provisions of the Northern Ireland Protocol under the EU-Britain Brexit Agreement and the "obligation of good faith" under that agreement.
In order to avoid a hard border on the island of Ireland and preserve the terms of the Good Friday Agreement, the protocol allows Northern Ireland to adhere to certain EU rules.
However, this is caused friction between the DUP and the UK government over the need for customs declarations and some checks on goods entering Northern Ireland from mainland Britain.
The UK government decided on Wednesday to extend until 1 October the grace period on the controversial agri-food controls between Britain and Northern Ireland to allow businesses to adapt to the new post-Brexit arrangements.
This is a "temporary" measure designed to avoid major disruptions "as part of a pragmatic and proportionate implementation of the Northern Ireland protocol," Northern Ireland Minister Brandon Lewis stressed in a written statement to Parliament.
Discussions on the subject are continuing with the European Union, he assured.
Irish foreign minister Simon Coveney called the move by the British government as "deeply unhelpful".
In a statement, he said: "At the EU-UK Joint Committee on 24 February, the UK reiterated its commitment to the proper implementation of the Protocol, as well as the implementation of all decisions taken in the Joint Committee in December 2020.
"The decision taken by the British Government today clearly undermines this commitment. A unilateral announcement is deeply unhelpful to building the relationship of trust and partnership that is central to the implementation of the Protocol".
Coveney had met with Lewis and Lord Frost earlier on Wednesday to discuss the issue.
"I made clear to them my regret that the UK had moved in a unilateral way, rather than working in continued partnership with the EU in accordance with the EU-UK joint statements of 11 and 24 February," he added.