The DUP have claimed the Brexit deal proposed by Boris Johnson, which has been all but rejected by the EU, has "flushed out" intentions to trap Northern Ireland in the backstop.
DUP leader Arlene Foster said comments alleged to have been made by the German Chancellor Angela Merkel during a phone call with the Prime Minister on Tuesday reveal "the real objective of Dublin and the European Union".
A Downing Street source was reported as saying that a Brexit deal is "essentially impossible" after the heated call between the prime minister and Ms Merkel.
Mrs Foster said reports that the German chancellor said that Northern Ireland should remain in the Customs Union forever were "beyond crazy".
"For the United Kingdom to be asked to leave a part of its sovereign territory in a foreign organisation of which the UK would no longer be a part and over which we would have no say whatsoever is beyond crazy.
"No UK Government could ever concede such a surrender.
"The Prime Minister’s proposals have flushed out Dublin’s real intentions to trap Northern Ireland in the EU Customs Union forever, where Dublin rather than the United Kingdom’s elected representatives would be in the driving seat.
"We will not accept any such ultimatum or outcome", Mrs Foster added.
Boris Johnson is set to meet taoiseach Leo Varadkar this week with both sides saying they still want a deal before the October 31 deadline.
Tánaiste Simon Coveney said last night there was a "lot of misinformation" being reported.
Adding that the Republic wanted a deal but that it "cannot come at any cost".
Sinn Féin deputy leader Michelle O'Neill, who is due to meet EU diplomats in Brussels this week, said she will be making it clear "that they have to remain firm on the need to avoid any hardening of the border, protect the Good Friday Agreement and protect our economy".
Ms O'Neill added: "The north's economy cannot withstand being excluded from the customs union and the single market and that is the message we will be bringing loud and clear to the EU."
SDLP leader Colum Eastwood said: "The British government, aided and abetted by the DUP, should set aside the Downing Street war games and finally listen to what people here are saying"..
Ulster Unionist Party leader Robin Swann said Northern Ireland was on "brink of a no-deal disaster".
"Politicians in the EU and our own government are treating Northern Ireland like a chess piece in a very high risk game," he said.
