The EU has urged the UK to drop the “political rhetoric” in the row over Brexit negotiations for Northern Ireland, revealing it will make what it described as “far-reaching proposals” to break the impasse next week.

The European Commission vice-president Maroš Šefčovič told a conference in Dublin he had a good relationship with the UK’s Brexit minister, David Frost, but that his threats to pull the plug on the Northern Ireland protocol were “not helpful”.

He confirmed the EU would finalise its response to UK demands that the protocol be substantially rewritten in the “middle of next week” and would then enter intense talks to try to find a solution. “I believe that the package of practical solutions we are putting on the table would be attractive … and I hope supported by majority of stakeholders in Northern Ireland.”

He also said he hoped it would meet the interests of the unionist parties who were vehemently opposed to the protocol.

What the EU was trying to deliver were “the best solutions, which will address the concern of the unionist community”, Šefčovič told the webinar at Ireland’s Institute of International and European Affairs. But he warned that the EU was not going to roll over to renegotiate the entire protocol just because the UK asked for this.

The protocol was the most difficult part of the withdrawal agreement to negotiate and involved “the best minds” on both sides over several years working on a solution to the problems Brexit caused in Northern Ireland. The EU would not negotiate the protocol “as the UK is requesting”, he said.

The commission has been working on counter-proposals to Lord Frost’s July command paper for the past month. Although Šefčovič declined to give details, they are expected to address the UK’s concerns over checks on food crossing the Irish Sea and barriers to medicine supplies between Great Britain and Northern Ireland.

It is unlikely, however, to concede to unionist demands that the role of the European court of justice should disappear. “I would say [they are] very far-reaching proposals and I sincerely hope that it will be seen as such by our UK counterparts and they engage constructively in our discussion, because I think we have to kind of move [away] from the political rhetoric, from the threats,” Šefčovič said.

“You are trying to do your most and what you hear from the other side is ‘it’s not good enough’ … these threats are definitely not helping.”

Šefčovič said the bloc would use all options under the treaties to protect EU interests but that there would not be a hard border if the UK decided to ultimately disapply the protocol.

A UK government spokesperson said it wanted “significant changes” to the protocol and reiterated that “any proposals must be subject to genuine negotiation”.

Earlier this week Frost said he would consider the EU’s proposals in good faith but he would only give the talks three weeks before deciding whether or not to trigger article 16, the mechanism to disapply parts of the protocol.

He warned the UK would act in a “robust” manner if the EU launched a retaliatory trade war in the event of talks collapsing during the article 16 process.