The Irish prime minister, Micheál Martin, has said the UK and EU need to “knuckle down” and resolve the dispute over Northern Ireland’s post-Brexit arrangements.
The UK’s Brexit minister, Lord Frost, will hold further talks with the European Commission vice-president, Maroš Šefčovič, on Friday, with the UK still warning it could unilaterally suspend parts of the Northern Ireland deal unless major changes are made.
But Martin said he was encouraged that progress was being made and the “mood music” had changed.
In a BBC interview, the taoiseach cautioned the UK against taking the step of triggering article 16 of the Northern Ireland protocol, which would suspend parts of the arrangements.
The protocol was put in place to prevent a hard border with Ireland by effectively keeping Northern Ireland in the EU’s single market for goods, but that meant checks on products crossing the Irish Sea from Great Britain.
Martin said the European Commission had put forward a “comprehensive package of measures” to address the concerns raised about the protocol, adding that some EU members thought Šefčovič had gone “too far” in the concessions he had offered to reduce checks.
He said he believed serious talks were taking place between the UK and EU, adding: “Where there is a will, there is a way, and I think both sides just need to knuckle down and get it resolved.”
Negotiations on the Brexit trade deal a year ago stretched until 24 December and Martin said: “Don’t leave it to Christmas Eve this year.”
Asked whether he could trust Boris Johnson, the taoiseach said: “I get on well with Boris Johnson on a personal level.”
On Thursday, Frost told peers that the option of using article 16 remained on the table despite speculation a deal was within reach.
Martin said “my own view is that unilateralism never works” and using article 16 would have a “very negative” impact.
In parliament, Frost said Brussels should not interpret his “reasonable tone” in talks to imply any softening of the UK’s position, and that article 16 was still “very much on the table”.
He told the House of Lords: “Whatever messages to the contrary the EU think they have heard or read, our position has not changed.”
Frost said an agreement was the best way forward but “I would not recommend any outcome from the negotiations that I did not believe safeguarded political, economic or social stability in Northern Ireland”.
While Frost and Šefčovič meet in Brussels, Martin will join leaders and ministers from across the UK and Ireland in Cardiff for a session of the British-Irish Council.
The Welsh first minister, Mark Drakeford, said it was a “timely opportunity to support dialogue and collective action between our governments, and this is more essential than ever given the current challenges we all face”.
Frost claimed the UK was “maximising the opportunities of Brexit” with Teesside freeport beginning its operations.
“Having left the European Union we now have the freedom to do things differently, including setting up new freeports to turbo-charge our trade with the world’s fastest growing markets,” he said.