Brexiteers who have suggested the Good Friday Agreement should be reappraised have been accused of being “reckless and irresponsible” by Dublin.
Owen Paterson, the former Northern Ireland Secretary and Leave campaigner, was one of three MPs who questioned whether the 1998 accord had outlived its usefulness.
The Irish border question could cause Brexit negotiations to run aground next month unless the European Commission is prepared to be more flexible in its approach, sources on both sides of the negotiations have warned.
Whitehall sources have admitted the Government still has no answer to how Britain can leave the single market and customs union without imposing a hard border between Ireland and Ulster - which would risk the very foundations of the Good Friday Agreement.
Simon Coveney, the Irish deputy prime minister, said scrapping the Good Friday Agreement was not the answer. He said: “Talking down (the) Good Friday Agreement because it raises serious and genuine questions of those pursuing Brexit is not only irresponsible but reckless and potentially undermines the foundations of a fragile peace process in Northern Ireland that should never be taken for granted."
Mr Paterson, together with the Antrim-born Labour MP Kate Hoey and the Conservative MP Daniel Hannan, insist that comments they have made in recent days about the need to review the Good Friday Agreement relate to the year-long suspension of power-sharing in Stormont, and not Brexit.
David Davis, the Brexit Secretary, said yesterday: “I’m not conscious of anybody talking down the Good Friday Agreement, certainly nobody in Government has.
"Everything that we’re doing is aiming towards ensuring we meet every aspect of it. So I don’t foresee that being a problem."
Boris Johnson, the Foreign Secretary, told the Commons there was “no reason whatsoever” why Britain should not be able to exit both the customs union and the single market while maintaining “frictionless” borders between Ireland and Northern Ireland.
However, sources in London and Brussels have admitted the Brexit negotiations could be “driven to the wall” in March unless the European Commission can show more flexibility in its approach to the Irish border question.
The rising concern emerged as talks continued in Brussels over how to translate last December’s fudged political deal over the Irish border into a concrete legal text due to be presented to EU member states later this month.
Senior sources said translating the UK’s December promise to maintain “full alignment” with the EU single market if other solutions failed, risked “blowing up” the political situation in London.
Negotiators are seeking to finesse the December deal which set out three options for the UK to make good on its pledge to avoid a hard border in Northern Ireland after Brexit.
The first was through the “overall” EU-UK trade agreement which is yet to be negotiated; the second was through a combination of “specific solutions” and technical fixes and the third - in the event the first two options failed to satisfy the EU – was that the UK would submit to “full alignment” with the parts of the single market and customs union that underpinned the Good Friday Agreement.
British negotiators are arguing that all three options need to be represented equally in the legal text - now due to be published on February 28 - in order to avoid re-igniting the political rows over the Irish border which so nearly derailed the negotiations last December.
However The Telegraph understands that a planned draft of the text places disproportionate emphasis on the third, fall-back option of “full alignment” which was rejected by leading Brexiteers who are determined to leave the Customs Union and Single Market.
One diplomatic source said: “Only spelling out the fall-back option would be a real mistake, and potentially catastrophic given the political sensitivities involved.”
Dublin and Brussels remain “highly sceptical” that the second option of using border technology and “trusted trader” schemes will be sufficient to avoid a hard border.