Taoiseach Leo Varadkar has told the British Prime Minister that her U-turn on the backstop in the past 48 hours has only served to reinforce Ireland’s belief that one is necessary.
During a phonecall this evening, Theresa May outlined why she wants Brussels to reopen the Withdrawal Agreement she negotiated.
But her argument was met with a blunt response from Mr Varadkar who said Ireland’s position remains “unchanged”.
Confirming the phonecall, a spokesperson for the Taoiseach said he had noted “that the latest developments had reinforced the need for a backstop which is legally robust and workable in practice”.
Mrs May indicated that she is engaged in “further consultations” are taking place in London.
“They agreed to stay in touch over the coming period,” an Irish government spokesman said.
As the UK Prime Minister prepares to return to Brussels in a bid to secure new concessions on the backstop, both Mr Varadkar and Tánaiste Simon Coveney offered thier most explicit rebuffs to her strategy yet.
EU Council President Donald Tusk has also sent a message to Mrs May, saying: “The EU position is clear and consistent. The Withdrawal Agreement is not open for renegotiation.
“Yesterday, we found out what the UK doesn't want. But we still don’t know what the UK does want.”
Earlier Mr Coveney warned the UK is "running out of road" on Brexit while strongly hinting that a delay beyond March 29 should now be considered.
In a ‘State of the European Union’ address in Dublin this afternoon, the Tánaiste rejected the idea of finding "alternative arrangements" to the backstop.
"There are currently no alternative arrangements, which anyone has put forward, which achieve what both sides are determined to achieve – to avoid a hard border, including any physical infrastructure or related checks and controls, and to protect the all-island economy, North-South cooperation and the Good Friday Agreement," he said.
"Believe me, this has been explored endlessly in the negotiations over the last two years. We have seen no alternative arrangements that meet this essential threshold.
"And we need a backstop or insurance mechanism based on legal certainty, and not just wishful thinking."
At the event, organised by the IIEA, Mr Coveney welcomed the fact a majority of MPs in the House of Commons have expressed a desire to avoid a disorderly Brexit.
But he added: "The best way to achieve this, as the Prime Minister has argued since November, is to agree the 585-page Withdrawal Agreement and the Political Declaration on the Future Relationship.
"The Withdrawal Agreement won’t be re-opened, but as the EU has continuously said, the Political Declaration on the future relationship can evolve if the UK Government changes its red lines."
However, Brexit matters became increasingly personal as former UK Brexit secretary Dominic Raab accused Mr Varadkar of leaking details of a confidential meeting.
Mr Raab also accused the Taoiseach of giving out "inaccurate" information about his Brexit proposals following his meeting with Tánaiste Simon Coveney last October.
The Telegraph and Financial Times reported Mr Raab had insisted Britain has the right to pull out of the backstop after three months.
And speaking to the Northern Ireland Affairs Committee on Wednesday, Mr Raab said this information was leaked by "the Taoiseach directly".
Mr Raab said on Wednesday: "The conversation I had with him (Mr Coveney) was leaked to the media in terms which were not factually accurate, in terms of the proposal that I had put forward, privately and confidentially at his request.
"It was leaked in an inaccurate and misrepresenting way by the Taoiseach directly."
A spokesman for the Government here denied the allegation, saying: "There is no basis to this allegation. Mr Raab should produce evidence to support it if he has any."s
St Helens North Labour MP Conor McGinn said it was a "very serious accusation" to maket.
Mr Raab added: "Everyone in the UK Government knows the approach that I have been suggesting in relation to the Brexit mechanism, knows that's not what I have argued for within the UK Government let alone to my Irish friends."
He described his meeting with Mr Coveney as "very constructive".
Mr Raab added: "We both wanted to make this work, I found him a great interlocutor and I urged him not to rule out looking at some of the other opportunities and mechanisms in dealing with the exit from the backstop and we agreed, at his request, to keep the meeting confidential.
"Check the media, I did not comment on it, it was only commented on not by Simon Coveney but by the Taoiseach, so ask the question of whether the account of what I was proposing was what the Taoiseach leaked to the media or presented to the media.
"I don't the know the conversation Simon Coveney had with the Taoiseach and I don't understand what motivation may or may not have been.
"All I'm telling you is that is simply not what I discussed or what I was proposing and I have kept it confidential."
Speaking earlier this morning, the Tánaiste expressed "disappointment" at the latest developments in Westminster.
"We have been through all of these things. We have tested them and we have found that they do not stand up to scrutiny, and now we have a British prime minister advocating again for the same things that were tested," Coveney told RTÉ's Today with Sean O'Rourke programme.
"What we are being asked to do here is to compromise on a solution that works and to replace it with wishful thinking. That's what's being asked of the Irish government and we won't do it."
He continued; "The big difference between [Brexit] and the challenge with the nurses [the nurses' strike] is that we had an agreement here.
"And the British prime minister signed up to it. She was part of the negotiations.
"Up to three days ago, she was a strong advocate for the need of a backstop.
"If you look at her speeches in Westminster in defence of the backstop, she was talking about owing it to the people of Northern Ireland."
Meanwhile the Taoiseach told the Dáil that the UK parliament has the power to stop threats of a no-deal Brexit.
Mr Varadkar said neither Ireland nor the EU were involved in creating the risk of the UK crashing out without a deal on March 29 next.
“The withdrawal agreement is not up for negotiation and it’s not going to be re-opened,” Mr Varadkar insisted in the Dáil. He added that there are no plans for an emergency EU leaders’ summit to discuss any potential changes to the EU-UK draft divorce deal.
Speaking in the Dáil, the Taoiseach said the UK government and the UK parliament had it in their authority to take “no-deal” away at any time.
He said London has the authority to do that, either by revoking Article 50 or by extending it. This provision in the Lisbon Treaty gives any EU state the right to leave.
“Ireland and EU are not threatening no deal,” Mr Varadkar said.
Fianna Fáil leader Micheál Martin said history would not look kindly upon the North being left voiceless on Brexit and he believed that had the assembly should have been up and running.
“Instead of the DUP promoting its pro-Brexit approach the majority would be able to pass resolutions for the benefit the North,” Mr Martin said.
But Sinn Féin leader, Mary Lou McDonald, said “meetings with the DUP until the cows come home” were of no avail. “Unless there is a real pressure on them to do business they are not going to do business,” Ms McDonald said.
Mrs May has said she will seek "legally binding changes" to the divorce deal but has been met with a blunt response from the EU with European Council President Donald Tusk, among others, backing Ireland in saying it was not up for renegotiation.
The Tánaiste said there were mechanisms to get around some of the challenges May faces but the only way to do so was through the accompanying political declaration on future EU-UK ties that he said can be renegotiated to ease concerns on the backstop.
He also challenged May to stand by her previous statements that the backstop was necessary to avoid a return of customs checks between British-run Northern Ireland and EU-member Ireland.
However, she was having to accommodate a wing in the Conservative Party who want a different type of Brexit, he said.
"She has outlined repeatedly that the backstop is not only desirable but necessary to reassure people in Northern Ireland so surely the responsible thing for the Irish government to do is to hold the British government to its word."
Additional reporting: Reuters
How best to explain the madness that has gripped the House of Commons in recent weeks? Maybe we should look to the Middle Ages and the mysterious case of the meowing nuns for some answers.