Stormont's Agriculture Minister has ordered a halt to Brexit agri-food checks at Northern Ireland ports.
DUP minister Edwin Poots, whose officials are responsible for carrying out Northern Ireland Protocol checks, said he had ordered his permanent secretary to stop them at midnight on Wednesday night.
It is yet unclear whether the senior civil servant in his department, Anthony Harbinson, will comply with the order.
DUP rivals at Stormont insist the Civil Service has a duty to comply with Stormont's legal obligations to carry out the checks under the terms of the Brexit Withdrawal Agreement.
Mr Poots said legal advice he had sought on the issue supported his view that he was entitled to stop the checks.
The move comes after he last week failed to secure the wider approval of the Stormont Executive to continue checks on agri-food produce arriving in Northern Ireland from Great Britain.
The minister argues that in the absence of Executive approval he no longer has legal cover to continue the documentary checks and physical inspections.
Mr Poots said: "I have taken legal advice in relation to my position from senior counsel.
"Earlier today I received that legal advice. It stated that at present there is presently no Executive approval for SPS (sanitary and phytosanitary) checks.
"The implementation of SPS checks requires Executive approval. A decision to initiate or continue such checks could not be validly taken in the absence of Executive approval.
"The advice concluded that I can direct the checks to cease in the absence of Executive approval.
"I have now issued a formal instruction to my permanent secretary to halt all checks that were not in place on December 31, 2020, from midnight tonight.
"I will prepare a paper for Executive consideration in the near future to seek agreement on a way forward."
Sinn Fein Deputy First Minister Michelle O'Neill branded the move a stunt.
She said the DUP move is motivated by poor opinion poll performances ahead of May's scheduled Assembly election.
Ms O'Neill tweeted: "This stunt is an attempt by the DUP to unlawfully interfere with domestic, and international law.
"DUP fixated on their own priorities, which are clearly at odds with where the wider community is at. Health, Jobs, Housing, Cost of living crisis is where the rest of us are focused."
Irish Foreign Affairs Minister Simon Coveney has said the decision to halt Northern Ireland Protocol checks would be a "breach of international law".
Speaking in the upper house of the Irish parliament, Mr Coveney said: "If a political decision is taken by a minister in Northern Ireland to stop all checks in ports on goods coming across the Irish Sea, coming into Northern Ireland, that is effectively a breach of international law.
"And I would remind everybody that the protocol is part of an international agreement.
"It was agreed and ratified by the UK and the EU. And its implementation is not only part of an international treaty, but it is part of international law.
"And so to deliberately frustrate obligations under that treaty I think would be a very serious matter indeed.
"It's essentially playing politics with legal obligations. And I certainly hope that it doesn't happen, as has been threatened."
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