The DUP have slammed the brakes on Brexit leaving Theresa May red-faced during crunch talks in Brussels.
It had appeared London and the European Union were about to strike a deal that would have allowed discussions to move on to trade.
But suggestions the pact might involve Northern Ireland remaining in the customs union and single market prompted a furious response from the Democratic Unionist Party who prop up the Conservatives’ minority Government.
It is believed May left discussions with Juncker and spoke to DUP leader Arlene Foster before returning and calling time on the talks.
One Tory source sarcastically told The New European: ‘The DUP appear to be running Brexit negotiations now – great.’
However after the talks collapsed European Commission President Jean-Claude Juncker did extend his deadline saying there would be further negotiations before the summit of the European Council on December 14. He added he was ‘confident’ further progress could still be made.
Sources had claimed a deal could see both Ireland and Northern Ireland following the same rules governing trade, to ensure that goods can continue to move freely across a ‘soft’ border with no checks.
But Foster said the DUP would oppose the deal if it meant the effective drawing of a new border in the Irish Sea between Northern Ireland and the rest of the UK if the Westminster Government decides it wants to diverge from EU rules.
Speaking at Stormont, she said: ‘We note the speculation emanating from the European Union exit talks regarding the Republic of Ireland and United Kingdom border.
‘We have been very clear. Northern Ireland must leave the EU on the same terms as the rest of the United Kingdom.
‘We will not accept any form of regulatory divergence which separates Northern Ireland economically or politically from the rest of the United Kingdom.
‘The economic and constitutional integrity of the United Kingdom will not be compromised in any way.
‘Her Majesty’s Government understands the DUP position.’
Suggestions rules could be different for Northern Ireland drew anger from other areas of the UK that voted Remain, significantly London and Scotland.
Scottish National Party leader Nicola Sturgeon said on Twitter: ‘If one part of UK can retain regulatory alignment with EU and effectively stay in the single market (which is the right solution for Northern Ireland) there is surely no good practical reason why others can’t.’
And London mayor Sadiq Khan said: ‘Huge ramifications for London if Theresa May has conceded that it’s possible for part of the UK to remain within the single market & customs union after Brexit. Londoners overwhelmingly voted to remain in the EU and a similar deal here could protect tens of thousands of jobs.’