Minister for Foreign Affairs Simon Coveney has said "trust has been damaged and eroded" between the EU and the UK due to the "hugely irresponsible" actions of the British government in signalling its intent to override elements of the Brexit Withdrawal Agreement.
Mr Coveney said that he has not yet spoken directly to his counterpart in Britain, but hopes to speak to Cabinet Office minister Michael Gove in the coming days.
"We're in a difficult place, it's been a very bad week for trust between the EU and the UK, mainly because of the approach of the British government which really has been quite extraordinary this week," Mr Coveney said.
British Prime Minister Boris Johnson is facing mounting criticism over his legislation overriding his Brexit deal.
The Internal Market Bill will see the UK government reserve the right to unilaterally interpret the protocol's rules on state aid and customs declarations.
The EU's legal advice says the Northern Ireland Protocol "forms an integral part of the Withdrawal Agreement... If adopted as proposed, this bill will be in clear breach of substantive provisions of the Protocol…"
Speaking in Cork, Mr Coveney said the British government has been saying for a number of months that it is not going to follow through on commitments in the political declaration," which was signed with the Withdrawal Agreement but which was supposed to shape the Future Relationship discussions.
He added: "If that wasn't bad enough, the British government this week has committed to break international law and break a treaty that it signed with the EU less than a year ago because they don't like how it's now transpiring."
These actions have left EU and other countries around the world "looking at the British government and saying, 'is this the actions of a trustworthy partner'," and so trust has been damaged and eroded this week but we have to focus on trying to rebuild that again," he said.
"Ireland needs a deal before the end of the year, so does the UK and certainly the EU would like a deal as well, so I think while we have to call out the hugely irresponsible actions of the British government this week for what it is, and be truthful about that.
"We've also got to focus on the bigger prize here which is how do we put all of this back together and how do we find a way of getting a deal before the end of the year."
The consequences of a failure to reach that deal, he said, will be Britain and Ireland trading on World Trade Organisation rules which will mean tariffs and possibly quotas, "which from an Irish perspective in terms of our trade with the UK, which is worth over €80 billion a year, would of course be very disruptive and very damaging and that's the last thing we need in a Covid environment that's putting a lot of pressure on the Irish economy too."
Asked why he thought the British government has behaved in this way during the last week, he said: "I think it's difficult to understand, apart from perhaps a deliberate strategy to introduce some real tension into the negotiations at this point, presumably because the British side feel that they can achieve some concessions and flexibility by doing that, from the EU.
"I think it's backfiring though and we'll see what happens in the British parliament this week in terms of debating this approach."
Mr Coveney said that from his perspective, "we'll focus on what we can do. On the EU side we work very closely with Michel Barnier and his team...and we will be focusing on trying to agree how to implement the Withdrawal Agreement and how to shape the Future Relationship agreement that's good for the UK and good for Ireland and of course good for the EU as well and that means getting a trade deal, even if it's a very thin and a very basic trade deal, that avoids tariffs and quotas."
Part of any deal will have to be a "governance model," Minister Coveney said, to ensure that "if something like this happens in the future, and Britain reneges on the commitments it's made, that we have a robust dispute resolution mechanism that can ensure that both sides adhere to the commitments that they've made".
He said that while he has not spoken directly to the British foreign minister in recent days, "very clear messages" have been sent through the Irish embassy.
"My counterparts in the UK have been busy people this week, trying to explain what the British government is doing, but rest assured, the Irish Government's views and my views are very clearly understood in Number 10."
Asked if the British side can be trust in any future negotiations, he replied: "The answer to that question has to be 'yes,' otherwise we'll never get a deal, but there is a lot of work to do to rebuild trust after the week that we've had."
Mr Barnier said in a tweet this morning that the NI protocol is not a threat to the integrity of the UK, adding "sticking to facts is also essential".
Protocol on IE/NI is not a threat to the integrity of the UK. We agreed this delicate compromise with @BorisJohnson & his gov in order to protect peace & stability on island of Ireland. We could not have been clearer about the consequences of #Brexit [1/2]— Michel Barnier (@MichelBarnier) September 13, 2020
Sticking to facts is also essential. A case in point: ???? is not refusing to list ???? as a third country for food imports (SPS). To be listed, we need to know in full what a country's rules are, incl. for imports. The same objective process applies to all listed countries [2/2]— Michel Barnier (@MichelBarnier) September 13, 2020
Sinn Féin's Finance spokesperson Pearse Doherty said there is fear and anxiety in border counties about the ongoing Brexit situation and that many thought the issue of a hard border had been "put to bed" with the Withdrawal Agreement.
He said the British government has provided funding to the NI Executive to set up testing checks for food and agriculture required under the agreement and said it understood what this meant.
The Donegal TD said Mr Johnson is also doubling down by committing to withdraw Britain from the Human Rights Act, which is enshrined within the Good Friday Agreement, which he said "would be a huge, huge issue for Ireland and internationally".
He said the Taoiseach should have acted sooner to discuss the issue with the British government.
Taoiseach Micheál Martin earlier told RTÉ's The Week in Politics that there had been a forthright exchange of views with the British prime minister.
Speaking on the same programme, Labour TD Duncan Smith said it appears that the Conservative Party, under Mr Johnson, is "intent on not only destabilising his own country, but destabilising the region".
He said what is happening now with the Internal Market Bill could cost jobs not only in the UK, but also in Ireland and throughout Europe.
Mr Smith said the Government needs to focus on being prepared for a no-deal Brexit.