DUP leader Arlene Foster has said her party's desire for a deal on Brexit will not be superseded by a willingness to accept any deal.
"An agreement which places new trade barriers between Northern Ireland and Great Britain will fundamentally undermine the constitutional and economic integrity of the United Kingdom. That is not acceptable," she said.
In a statement on Tuesday night, reacting to an announcement of a deal between the UK and the EU on Brexit, Ms Foster said “such a deal will weaken the Union”.
“No unionist Prime Minister could argue that such a deal is in the national interest,” she said.
"It would be democratically unacceptable for Northern Ireland trade rules to be set by Brussels. Northern Ireland would have no representation in Brussels and would be dependent on a Dublin government speaking up for our core industries."
She also said she was “ heartened by friends of the Union on both sides of the House and across the United Kingdom who have pledged to stand with the DUP in opposing a deal which weakens the Union and hands control to Brussels rather than Parliament”.
“These are momentous days and the decisions being taken will have long-lasting ramifications.
“The Prime Minister must win the support of the Cabinet and the House of Commons. Every individual vote will count.”
Sinn Féin leader Mary Lou McDonald said that while politicians awaited sight of the full text of the draft agreement it was a “matter of concern that some are presenting the backstop agreement as temporary”.
“Brexit is for the long term and what is required is a durable, permanent and legally robust agreement that safeguards Irish interests and ensures there is no hard border on the island of Ireland,” she said.
Protection of businesses
SDLP leader Colum Eastwood urged the DUP to carefully and honestly consider what was on offer. "Their job is to protect people in Northern Ireland, to protect businesses in Northern Ireland," he said.
There have been reports that while the UK would remain in the customs union that there would be specific arrangements for Northern Ireland that would include some regulatory checks of goods coming into the North.
Mr Eastwood said: "A few cows being checked coming into Larne does not undermine the union. What is undermining the union is the way in which the DUP and hard Brexiteers have carried on over the past couple of years."
Ulster Unionist leader Robin Swann said there "must be no ambiguity, constructive or otherwise, in any deal about Northern Ireland's place within the union in a post-Brexit UK".
"To do otherwise would be a serious blow against the Belfast Agreement and the principle of consent and will set a dangerous precedent for the future," he said.
“The bottom line for the prime minister, the Conservative government and their partners in the DUP must be the achievement of a sensible deal which respects the result of the referendum and maintains the integrity of the United Kingdom,” Mr Swann added.
Alliance deputy leader Stephen Farry said reports of a deal were encouraging. "But we must remain cautious ahead of the publication of any text and in anticipation of the internal politics of the UK government and parliament playing out," he said.
“For Alliance, an open-ended backstop in place until or unless it is superseded is critical to protect the Good Friday agreement and to avoid a hard border in Ireland,” he said.
