The British cabinet minister in charge of international trade has insisted that no decision on the Irish border can be made until Brexit talks move on to the second stage.
The comments from Westminster’s international trade secretary Liam Fox will put him directly at odds with both Ireland and the EU.
EU negotiators have long-warned that talks cannot move on to the UK's future trading relationship with the EU until “sufficient progress” is made on three key issues – the border, citizens rights and the so-called Brexit bill.
The Taoiseach meanwhile, has made it clear that Ireland will block the talks from moving forward unless a solution, ensuring there will be no hard border, is “written down in practical terms in the conclusions of phase one."
Meanwhile in an interview with the Observer newspaper published this morning, the EU Agriculture Commissioner Phil Hogan said the best solution for everyone would be for entire UK to remain in the customs union.
He said it was a "very simple fact" that remaining in the single market and customs union would end the standoff, adding that Ireland will "continue to play tough until the end."
However, speaking on a visit to New Zealand this morning, Mr Fox said: "The UK is going to be leaving the customs union and the single market.
"We've always had exceptions for Ireland - whether it's in voting rights or residence rights in the UK - we've always accepted a certain asymmetry,” he said.
"That will have to be part of whatever agreement we come to with the EU.
"But we can't get a final answer to the Irish question until we get an idea of the end state - and until we get into discussions with the EU on the end state that will be very difficult.
"So the quicker we can do that the better.”
He added: "We're still in the position where the EU doesn't want to do that and we're getting quite close now to 2018, when we'll be talking about 'next year' when we leave the EU.
"So for all the reasons - international as well as European - I think we have to get there faster than we're doing at the present time."
Following the interview Labour's shadow chancellor John McDonnell said he was "worried" about the comments.
He told ITV's Peston on Sunday: "I think the one thing that we don't want to do is jeopardise any movement quickly, because we need movement to enable us to get into the proper trade negotiations.
"So I'm hoping that isn't a Downing Street sanctioned statement that's he's made."
It came after Liberal Democrat leader Sir Vince Cable told Sky News there was a 20% chance Brexit "won't happen."
He said: "There is a distinct possibility Brexit won't happen. I would currently put the chances at about 20%, but that is likely to become greater."
Ireland has consistently warned that there can be no return to a hard border – with both the EU and the UK offering promises that it can be avoided.
It has been suggested in many quarters that a border could be avoided if Northern Ireland is given special status to remain in the customs union, even if the rest of the UK does not.
However, yesterday the DUP leader Arlene Foster warned that her party will not support any Brexit deal that creates barriers to trade between Northern Ireland and Britain.
Addressing the annual DUP conference, she admitted no one wants to see a hard border on the island of Ireland - however, she said her party will not accept any suggestion that the North should remain within the customs union after the UK leaves the EU.