Stormont assembly members have clashed over the prospect of the British government overriding elements of the Brexit withdrawal deal.
The issue was the first item of business in Parliament Buildings in Belfast as the assembly returned from summer recess.
The debate came in response to a Financial Times report that the British government will seek to introduce domestic legislation to supersede parts of the Northern Ireland protocol governing state aid and customs arrangements.
Under the protocol negotiated in the withdrawal deal, Northern Ireland continues to follow single market rules for goods and administers the EU's customs code at its ports.
It was designed to avoid a hard border on the island of Ireland but unionists have been vehemently opposed to it, insisting it instead creates an economic border between Northern Ireland and the rest of the UK.
The protocol will require extra regulatory checks on some goods entering Northern Ireland from the rest of the UK, with the expansion of infrastructure to screen animals and food products.
The British government has insisted there will be no new physical customs infrastructure in Northern Ireland, but additional administrative processes on good crossing the Irish Sea are set to be required.
The issue was raised in the assembly as a matter of the day by the SDLP.
The party's South Belfast MLA Matthew O'Toole was highly critical of the British government.
"That the UK government would seek to use what looks like legislation in the House of Commons to undermine core tenets of the protocol is deeply worrying and disappointing, but perhaps not surprising," he said.
"Its attitude to Northern Ireland and our institutions throughout this process has been little better I am afraid than contemptuous, certainly since Boris Johnson became prime minister.
"The protocol is no one's ideal situation for Northern Ireland, the protocol is not something any of us five years ago, before the Brexit process, would have asked for.
"However, it is now lodged in the United Nations in international law. It is there to protect our society and our island from a hardening of the border on this island.
"It's necessary, it's essential, it becomes all the more essential when the UK government signals that it wants to strike the hardest possible Brexit"
The DUP's Christopher Stalford struck a very different note.
He said he hoped the speculation proved correct and the protocol was overridden.
"We will be doing all we can to act in the interests of Northern Ireland within the United Kingdom and it's precisely because we are acting in the interests of Northern Ireland that we, as a party, are opposed to this protocol," he said.
"It will damage our economy, because it hives us off from our largest market, the GB market.
"As a sovereign and now thankfully independent country, the United Kingdom has the right to legislate upon the regulation of its own internal market.
"It is to be hoped that this is what is about to be undertaken this week by the government."
The South Belfast member added: "For the sake of our country, our small businesses and our economy as a whole, I hope that the speculation is correct."
