Tánaiste Simon Coveney has said the Withdrawal Agreement is not up for renegotiation and he dismissed the call by the Polish Foreign Minister for a five-year limit on the backstop as not reflecting the EU position.
Speaking in Brussels during a meeting of EU foreign ministers, Mr Coveney said: "We have spent 18 months or so in a difficult negotiation that resulted in a Withdrawal Agreement and all of the detail that was part of that.
"It's been made very clear repeatedly that the Withdrawal Agreement is not up for renegotiation."
The Minister for Foreign Affairs responded to the remarks by his Polish counterpart Jacek Czaputowicz about the backstop.
Mr Czaputowicz told the Rzeczpospolita newspaper: "If Ireland turned to the EU about changing the agreement with Britain with regard to the provisions on the backstop so that it would only apply temporarily - let's say five years - the matter would be resolved."
He added: "I don't know if it's feasible - if Ireland is ready to put forward such a proposal, but I have an impression that it might unblock the negotiations.
"We need bold action. If Ireland was to ask the EU to change the deal with the British, the backstop provisions, so that they would only apply for, say, five years, the issue would be resolved."
Mr Coveney said Mr Czaputowicz had made a similar suggestion during his visit to Dublin in December.
He said he had made it "very clear" to the minister on that occasion that putting a time limit on an insurance mechanism effectively meant it was not a backstop at all.
He said the Polish minister's remarks did not reflect EU thinking.
Speaking in Brussels @simoncoveney says the Withdrawal Agreement is not up for renegotiation, and he dismissed the call by the Polish foreign minister for a five year limit on the backstop as not reflecting the EU position.— Tony Connelly (@tconnellyRTE) January 21, 2019
Mr Coveney told reporters: "This was probably an attempt to be helpful. Poland has more citizens in the UK, even more than Ireland.
"I don't think his intervention reflects EU thinking here. In fact, I know it doesn't.
"If you listen to what other EU leaders have been saying, what the presidents of the EU institutions have been saying, and what the chief negotiator has been saying. They're all saying the same thing. That we can't reopen the Withdrawal Agreement for renegotiation."
He said the way to solve the problem was to look at the future relationship declaration.
"If the UK is willing to do that then the EU will try to respond in a generous way," he said.
German Foreign Minister Heiko Maas also rejected the proposal.
"I am completely with my Irish colleague. He has already said what he thinks of it, which is nothing," he said.
Mr Coveney also held a bilateral meeting with British Foreign Secretary Jeremy Hunt.
The Tánaiste said he had received assurances that, contrary to newspaper reports, the UK was not seeking to change the Good Friday Agreement.
He said: "My position with very Jeremy Hunt was very clear today. He understood my position before today, but he certainly understands it after the meeting, and that is that Ireland remains firmly supportive of the Withdrawal Agreement in full, but we will listen carefully to what is said in Westminster today."
Additional reporting Reuters