First Minister Arlene Foster believes “majoritarianism” is back in Northern Ireland as unionists appear outnumbered in their push back against the protocol agreement.
The Sinn Fein leadership, however, played down the issues arising from the Northern Ireland protocol as “teething problems”.
Mrs Foster, deputy First Minister Michelle O’Neill, the UK Government and the European Union met on Wednesday to discuss the protocol after Brussels performed a swift u-turn on invoking article 16 of the protocol last week.
As part of the Brexit Withdrawal Agreement, the protocol sees physical inspections on goods entering Northern Ireland, creating a de facto Irish Sea border - something which has angered unionists.
Article 16 allows either side to disregard certain measures should they feel it is causing major problems.
Ireland’s Foreign Minister Simon Coveney insisted that the protocol will not be scrapped and said it was “not realistic” to drop it with no alternative offered.
DUP leader Mrs Foster told Radio Ulster’s Good Morning Ulster that all of Northern Ireland’s unionist politicians are against the protocol.
Deputy First Minister Michelle O’Neill (Liam McBurney/PA)
The deputy first minister said the DUP’s five-point plan to undermine the protocol was “very unrealistic”.
“It’s also ironic given the fact that these were the Brexiteer champions,” Ms O’Neill told RTE Radio 1.
She said the DUP and Tories "delivered us Brexit - a Brexit that everybody warned would have consequences".
“The outworking of which we’re dealing with today with the new trading realities that now exist.
“There are things that are the new realities and you can’t do anything about it in a post-Brexit world.
“However, there are things that need to be ironed out and there are kinks in the protocol being implemented because we’re not even six weeks into this operation.”
Ms McDonald added on BBC Radio 4: “We need cool heads, we need calm mature leadership and these teething problems that do exist need to be identified and need to be ironed out.
“I believe that there are huge mechanisms and flexibilities for that to happen. We don’t need melodrama.”
Elsewhere, Sinn Fein’s Junior Minister Declan Kearney said on Newstalk that unionists were “dialling up the rhetoric, whipping up tensions unnecessarily, and potentially taking us into a situation where none of us want to be”.
Arlene Foster dismissed suggestions she or her party were whipping up tensions.
As part of their five-point plan opposing the protocol, the party's petition to the UK Government went live on Thursday morning.