The leader of the Best for Britain campaign for a second referendum, Eloise Todd, said: "When the history of Brexit is written in a few years' time the backstop and the UK's decisions around it will be held up as an example of how not to negotiate".
Last weekend, the London-based The Daily Telegraph reported that British chief negotiator for the Brexit, Dominic Raab, privately asked Coveney for the UK's right to unilaterally deactivate the emergency plan.
There appears to be a softening on the EU side to an all-UK customs union replacing the Northern Ireland specific text, but that would require an acceptance by Downing Street that it would in effect be a permanent arrangement.
"We are making good progress on the future relationship, and 95% of the Withdrawal Agreement has been settled".
The DUP's Donaldson, whose party has repeatedly criticized Dublin's approach, said a no-deal Brexit would have serious consequences for Ireland's economy and he "can't understand why Irish Government seems so intent on this course".
British Prime Minister Theresa May will bring plans to avoid a hard Border to her divided cabinet tomorrow.
"In March the United Kingdom agreed this backstop will apply "unless and until" a close future relationship eliminates any need for border infrastructure or related checks and controls".
Cabinet members are due to discuss the status of the Brexit talks on Tuesday morning at their regular weekly meeting, but No 10 was earlier indicating that any update for senior members of the British government was not likely to be substantive because insufficient progress had been made.
The former attorney general told BBC Radio 4's Today programme: "At the end of the day it highlights why the entire enterprise is questionable, because in fact what we are likely to end up with is leaving the European Union but staying in a relationship of sufficient dependency on it without influence as to call into question the whole project". But that goal has been complicated by May's intention to take Britain out of the EU customs union and single market. "That is why we are increasingly positive on the expectation of reaching a deal".
In a letter to Mrs May they say Parliament should not be bound by the 2016 vote any more than it should be by the 1975 referendum that took Britain into the European Union, especially when there are question marks over its validity.
The talks could extend into December, but Theresa May would rather avoid this scenario as it would ensure that there would be no chance of securing the parliamentary vote over or before Christmas.