Mrs Long added that while the backstop is essential if Brexit is to happen, the Prime Minister’s “best option” was to return to the people, giving them the final say.
“For Northern Ireland, this represents further instability and challenge for jobs and growth, and compounds political instability,” she said.
“Northern Ireland voted to remain, and staying in the EU continues to be the best way forward. The local business community and civic society, and parties representing the majority of opinion, are willing to be pragmatic in supporting the backstop, recognising that it protects this region from the worst effects of Brexit and offers us the economic opportunity to have a foot in both camps.
“If Brexit is to happen, then the backstop must be the bottom line. Instead, MPs, including those who claim to be representing Northern Ireland’s interests, are rejecting the Withdrawal Agreement and the stability it offered, placing it in jeopardy, whilst offering no alternative in return.
“It now looks increasingly likely that Brexit is undeliverable. Those who campaigned for it are entirely responsible for the failure. They had no plan and completely unrealistic expectations of the UK’s negotiating strength against 27 other nations in the EU.
“Even at this late stage and despite holding senior cabinet positions through the negotiations, they have no single, coherent vision of what future arrangements they want to deliver, let alone how they would achieve them.
“Instead of accepting Withdrawal Agreement which would ensure an orderly, managed Brexit could proceed, they instead want to drag the country over a cliff edge into a chaotic future, in which the only certainty is that people will be worse off than they are now.
“The best option now is for the Prime Minister to return to the people and give them the final say on this debacle. Let the public decide whether they want to vote for the reality of Brexit – a deal worse than we have now, a future poorer than we are now – or whether they want to stop this act of national self-harm and rescind Article 50.”