Border checks are set to be suspended in Northern Ireland's ports from midnight in a fresh Brexit row.
DUP minister Edwin Poots ordered officials to stop checks on food and farming goods coming into Northern Ireland, which are required under Boris Johnson's Brexit deal.
The UK and the EU agreed that goods from Great Britain must be checked at Northern Ireland's ports to ensure they comply with EU laws.
But Mr Poots argued the checks are unlawful after seeking legal advice.
Speaking at Stormont, Mr Poots said: "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."
But it is unclear whether the senior civil servant in his department will comply with the order.
Northern Ireland's Deputy First Minister Michelle O'Neill branded the decision a "stunt".
She said: "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."
The move comes amid ongoing tensions between the EU and the UK over a key part of the Brexit deal, known as the Northern Ireland protocol.
The protocol was designed to prevent a return to violence on the island of Ireland by avoiding a land border between Northern Ireland and the Republic of Island.
Instead, a trade border was effectively created in the Irish Sea.
Mr Johnson has spent most of the past two years trying to tear apart the Brexit deal he negotiated to reduce these checks, which have caused red tape and delays for businesses and consumers in Northern Ireland.
Foreign Secretary Liz Truss has taken over the negotiations following the resignation of Brexit Minister Lord Frost, who repeatedly threatened to unilaterally tear up the deal.
The DUP are opposed to the NI protocol, as they fear it means Northern Ireland is treated differently to the rest of the UK.
