The British Prime Minister has insisted she is sticking to her proposals for avoiding a hard border with Ireland after Brexit.
Downing Street this afternoon denied reports that officials in Brussels had rejected all of the UK's suggestions on the issue.
A spokesperson said the UK remains confident a solution can be found that works for everyone - provided all sides can work together productively.
The spokesperson insisted two existing proposals remain the basis for negotiations.
The Tánaiste Simon Coveney, 12-04-2018. Image: Sam Boal/RollingNews
Meanwhile, the Tánaiste has confirmed that Ireland's position has not changed and insisted that negotiators secured a commitment from the British Government on the issue:
Simon Coveney confirmed that Ireland's position on the border post-Brexit has not changed.
"We have said that we need solutions on key things for Ireland," he said.
"The Irish border being the most difficult one to solve but also being the one that we have the strongest political commitment from the British Government on.
"Of course we also want to protect the Good Friday Agreement in all of its detail.
"Protecting North/South cooperation on the island of Ireland - these are hugely important issues."
It comes after claims, published in the Daily Telegraph, that the European Union has rejected all the British proposals on the border.
This is apparently because none of the customs options put forward would work.
It is thought this could cast doubt on the UK's ability to leave the customs union.
Senior EU diplomatic sources told the newspaper that a plan by British Prime Minister Theresa May for avoiding a hard border in Northern Ireland was subjected to a "systematic and forensic annihilation" this week at a meeting between senior EU officials and Britain's lead Brexit negotiator.
The source was directly briefed on the meeting in Brussels on Wednesday.
"It was a detailed and forensic rebuttal. It was made clear that none of the UK’s customs options will work. None of them," they added.
British Prime Minister Theresa May | File photo
A British government spokesperson said Britain is continuing an "intensive work programme to engage" all the scenarios set out in a joint report in December, which was agreed by Mrs May and European Commission President Jean-Claude Juncker.
It included three options for the Irish border, with Britain backing a close economic relationship that makes customs checks unnecessary or implements technological solutions that would make them near-frictionless.
But in February, the EU published a version which only included the third "backstop" option, which effectively draws a customs border down the Irish Sea.
Mrs May said it was a scenario "no British Prime Minister could ever agree".
She is facing pressure ahead of a vote in the London's House of Commons next week on keeping the UK in the customs union. The same issue was defeated in the House Lords.
"Fantasy island unicorn model"
Mrs May could have to keep Britain in the customs union to avoid a hard border with Ireland.
According to the Telegraph, Mrs May's suggestion of a "customs partnership", where duties destined for the EU were collected on its behalf, was thrown out because it was too expensive, put too much responsibility on businesses and couldn't be implemented outside of the EU's mechanisms.
Britain's former ambassador to the EU, Ivan Rogers, has warned that UK hopes of finding a technological solution to the Irish border issue are being regarded as a "fantasy island unicorn model" by other European capitals.
He told those at the Policy Exchange think-tank in London: "The Brits are focused above all on Option B - the technological solution. That, candidly, from everything I've heard from various places is still viewed as a bit of a fantasy island unicorn model.
"The Irish and Brussels in particular - but I think backed, as far as I can see, by Berlin and Paris - have said the only solution to this is the so-called backstop Option C, which is what the commission put in print and got the toxic reaction both from the DUP and the Prime Minister."
A British government spokesman added: "We have been clear that we will protect Northern Ireland's place in the UK internal market."