Agriculture Minister Edwin Poots has threatened legal action over the post-Brexit trade arrangements for Northern Ireland.
On Tuesday he said that a senior barrister has been instructed to examine the Northern Ireland Protocol.
Mr Poots told the Stormont assembly he would start judicial proceedings once the examination was complete.
The Protocol is the part of the Brexit deal which created the Irish Sea trade border.
It is opposed by Northern Ireland's unionist parties which have said it undermines their place in the UK.
Under the terms of the Brexit withdrawal treaty, the Protocol can only be removed by a majority vote of the assembly, with one due in 2024.
The Stormont agriculture department - which Mr Poots oversees - is responsible for building and operating the border control posts at which checks on goods entering Northern Ireland from Great Britain take place.
Mr Poots, who is also a contender for the Democratic Unionist Party (DUP) leadership, told the assembly that "ultimately the Protocol needs to go".
He said that in January, he had asked his officials to get an opinion on the Protocol from a senior QC, who has been appointed and is scrutinising the legislation.
"On completion, it is my intention to lodge judicial proceedings against the Protocol," Mr Poots said.
"I would hope that the Department for Economy and Department for Health - because this is having major implications for both medicines and medical devices - will join with me in taking an action against the European Union and UK government for the damage that it is inflicting on all of the people of Northern Ireland."
In March, the UK government changed how the Protocol was being implemented without EU agreement.
It delayed the introduction of new sea border checks on food, parcels and pets.
It also moved unilaterally to ease the trade in horticultural products from Great Britain to Northern Ireland.
Mr Poots said that when that grace period ends, it is estimated there will be 15,000 checks each week at Northern Ireland's ports.
This month, UK Agriculture Secretary George Eustice told Mr Poots to progress new border control posts "without delay".
The posts are operating from temporary facilities but the EU said work needs to begin urgently on permanent premises.