Tánaiste and Minister for Foreign Affairs Simon Coveney has flatly dismissed a UK proposal to create a string of customs posts along both sides of the Irish border in order to replace the backstop.
The proposal was contained in a so-called "non-paper" that had been submitted by the UK negotiators to the EU Brexit taskforce.
In a tweet, Mr Coveney said that the non-paper was a non-starter.
Non-Paper = Non-Starter. Time the EU had a serious proposal from the UK Govt if a #Brexit deal is to be achievable in October. NI and IRE deserves better!— Simon Coveney (@simoncoveney) September 30, 2019
The Tánaiste added that it was now time the European Union had what he described as "a serious proposal" from the UK government, if a deal on Brexit was to be achieved in October.
In a rebuke to the UK, Mr Coveney concluded by saying that Northern Ireland and the Republic of Ireland "deserves better".
This evening, Mr Coveney said that he did not see any of the leaked draft proposals reported by RTÉ News.
Speaking on RTÉ's Drivetime, the Tánaiste said he had spent a lot of last Friday afternoon with the EU's chief Brexit negotiator Michel Barnier and his taskforce.
He said they knew some technical papers had been produced by the UK side, but that he had not seen any of them, and still has not seen any of them.
He said Mr Barnier made it very clear that none of the papers they had received from the UK side, which he said were referred to as non-papers, came close to being the basis of agreement.
Meanwhile, the Cabinet has been given an update on no-deal Brexit plans this morning.
There has been a particular focus on transport and proving supports for businesses that would be worst hit by a hard Brexit.
A meeting heard there remains a stubborn group of businesses that still have not registered for the necessary revenue number to allow them continue to export to the UK in the event of a disorderly Brexit.
Government sources say that all sides know that the proposals in the UK 'non-paper' is never going to form the basis of an agreement.
The Government is again calling on the British government to table full proposals to the European Union's taskforce this week.
Opposition politicians have been united in their condemnation of the UK proposal.
Fianna Fáil Deputy Leader Dara Calleary flatly rejected the UK non-paper, saying a hard border, with its infrastructure, is something which "we cannot tolerate on our island".
Sinn Féin President Mary Lou McDonald said the UK proposal was absolutely out of the question - describing it as "vexatious and almost menacing".
Ms McDonald said the UK's backstop changes amounted to a "sabotage" of the peace process in Northern Ireland.
"We have explained this (the importance of no border checks) in painstaking detail to Mrs May in her time and now Prime Minister Boris Johnson," she added.
"Privately both always said that they understood that and therefore it is all the more disgraceful that they would try and sabotage the peaceful dispensation on our island.
"Boris Johnson voted for the backstop because in a moment of perhaps rare lucidity he recognised that was the bottom line to protect the island of Ireland. I only hope he returns to that position."
Labour leader Brendan Howlin, meanwhile, described the plan as "entirely unacceptable", adding: "I don't think anyone would table such proposals with a view to securing an agreement."
Richard Boyd Barrett, of People Before Profit, said the UK proposal illustrated the "complete disregard which Prime Minister Johnson has for the political and economic future of Ireland".
Former taoiseach Bertie Ahern said the British Prime Minister and his advisers know that the idea of customs clearance centres would "not be a runner".
Mr Ahern says it does not seem likely that the gap between the UK and the EU can be bridged before 31 October.
He told RTÉ's Today with Sean O'Rourke that Mr Johnson had a wonderful opportunity last week, with the Supreme Court judgement, to seek an extension from the EU until the end of April.
Mr Ahern said he did not believe that the DUP wanted a no-deal Brexit and it would be in the DUP's interest to find a resolution.
Elsewhere, the Northern Ireland Director of the umbrella UK business organisation, the CBI, has described the details about border checks as ludicrous and said they are going nowhere.
Speaking to BBC Radio, Angela McGowan said the proposals would jeopardise the peace process and put the Irish and Northern Ireland economies at risk.
She said the plan in the so called 'non-paper' would amount to something worse than the previous border that was in place and that it flies in the face of all the promises that for Northern Ireland no border would be put on the island.
She said to have checks along the border in this fashion amounts to ludicrous proposals and in some way "smacks to me that they [The British Government] don't want to be taken seriously, they are perhaps not looking to get a deal if they are putting this on the table at this stage".
Ms McGowan said under the proposals companies would have to stop, there would be queue and checks, lorries and vehicles would have to pull over, there would be interruptions to the supply chain, it will interrupt the agri-food sector in Northern Ireland.
Additional reporting Tommie Gorman, PA