One of the key architects of the peace process has appealed to Arlene Foster to think beyond the DUP's current position of influence after the former First Minister claimed the Good Friday Agreement was "not sacrosanct".
Former SDLP Deputy First Minister Seamus Mallon joined the chorus of critics following her comments in a Daily Telegraph interview.
He said that, sadly, he was "not surprised" by Mrs Foster's rhetoric.
"Even when she was First Minister she was never really in tune with the objectives of the Good Friday Agreement, which seek to create equality of life here in the north of Ireland," he said.
In the interview, Mrs Foster praised Boris Johnson's "positive" Brexit vision and said it was wrong to think the Good Friday Agreement was sacred when determining any final deal with the EU.
She also said it was "deeply frustrating" to hear people suggest that "we can't touch" the 1998 accord which has been held up as "a sacrosanct piece of legislation" by those who have misinterpreted it.
Mr Mallon urged Mrs Foster to think beyond the political terrain which her party currently finds itself on, which will inevitably shift.
"Let me just say this to Mrs Foster if I may: this agreement you have with the Tory Government is transient and will pass away, but the foundations upon which the Good Friday Agreement was built will last," he said.
"Those foundations of peace, justice and equality is something you should think about."
In a stinging critique, Mr Mallon said her words only bolster his belief that she "finds great difficulty with all of the principles" which underline the Agreement.
Mrs Foster's comments also provoked criticism from Sinn Fein president Mary Lou McDonald and Taoiseach Leo Varadkar.
Ms McDonald called on the Irish Government to make it clear the Good Friday Agreement was "not a chip to be bargained".
She warned that Mrs Foster's comments "revealed a reckless disregard" for the peace process, which was endorsed by the vast majority of people on both sides of the border in the 1998 referendum.
"It should be remembered that Arlene Foster left the UUP, which supported the Good Friday Agreement, to join the anti-Agreement DUP," she added.
"It appears the DUP leader has learnt nothing over the past 15 years."
Ms McDonald also claimed Brexit was "incompatible" with the Good Friday Agreement and called on the DUP to "commit to the full implementation of the Good Friday, and other agreements, rather than seeking to undermine them", which she said would lead to the restoration of devolution.
Addressing the Dail, Mr Varadkar said that while it was factually correct to say the Agreement could be changed, he sees Dublin's role as "co-defenders" of an international agreement and vowed to protect its "primacy".
"I don't think we should forgot all that has been gained by the Agreement," he said.
"A peace in Britain and Ireland, power-sharing most of the time in Northern Ireland, and ever closer co-operation between north and south."
Mr Varadkar added the peace deal "is not a piece of British legislation; it is an international agreement between the British and Irish Governments, as well as a multi-party agreement among the various parties".
"While it may be factually correct to say that the Good Friday Agreement, just like any international treaty, could be changed, it can only be changed with the agreement of British and Irish Governments, and can only be changed with the consent of the people of Northern Ireland, and indeed across cross-community consent.
"It is not something that can be changed by any one political party or by any one government.
"Certainly, as far as this government is concerned, the Good Friday Agreement is not up for negotiation in these talks over Brexit."
Tanaiste Simon Coveney took to social media to rebuke Mrs Foster, who addressed delegates attending a DUP fringe event at the Conservative Party Conference in Birmingham yesterday.
"I have respect for Arlene, but she is wrong on this," he wrote on Twitter.
He too vowed to defend and protect the Agreement.
UUP leader Robin Swann branded Mrs Foster's comments as "strategically short-sighted" and said the principle of consent "should be sacrosanct" to all unionists.
"The reality is that the principle of consent is what binds us to the United Kingdom, it is the best settlement for unionists," he said.
"We should be looking to build on this principle and ultimately remove the changes made at St Andrews to finally do away with the sectarian politics which continues to plague us to this day."
Alliance leader Naomi Long called on Mrs Foster to clarify her comments and pointed out that there is "a world of difference" between reforming structures with the consent of the population "and undermining the spirit of the GFA" against the wishes of the electorate.
She also warned that a "headlong rush" towards a hard Brexit could render the founding principles of co-operation and interdependence as collateral damage. "Its success relies on every one of us, including Arlene Foster, showing it the respect it deserves and understanding how significant it is in building towards the united community we all desire," she added.
But yesterday Mrs Foster said the Agreement is not infallible and has already been "changed on a number of occasions" citing the St Andrews Agreement and Stormont House Agreement as examples. "It is a thing of its time and changeable," she added.