British Prime Minister Boris Johnson has vowed to take action on the Northern Ireland Protocol if the EU refuses to ditch "absurd" aspects of the post-Brexit trading arrangements.
Mr Johnson said his government was currently working on "sandpapering" the protocol, which governs Irish Sea trade post-Brexit, to address some of the concerns about trade disruption.
In an interview with BBC NI's Spotlight programme, the prime minister was also questioned on the potential of a future border poll.
Mr Johnson said he could not envisage such a vote for "a very, very long time to come".
The programme also interviewed Taoiseach Micheál Martin, who insisted the protocol was not tearing the UK apart.
The new trading arrangements have been cited as a factor behind the recent upsurge of violence in loyalist areas in Northern Ireland.
Loyalists believe the new economic barriers between the region and Great Britain have weakened their place in the UK.
The protocol requires a range of new regulatory checks on agri-food goods entering Northern Ireland from the rest of the UK.
Some GB goods are banned under the arrangements. Commercial goods also need to undergo various customs processes.
The protocol has yet to be fully implemented with various exemptions on checks currently in place.
The EU has taken legal action against the UK for its decision to unilaterally extend some of those grace periods amid continuing talks between the two sides on ways to ease the red tape burden.
Mr Johnson has repeatedly warned that he will trigger a mechanism to suspend the protocol - Article 16 - if changes to the arrangements cannot be agreed.
"If we can't make enough progress and if it looks as though the EU is going to be very, very dogmatic about it and we continue to have absurd situations so you can't bring in rose bushes with British soil into Northern Ireland, you can't bring British sausages into Northern Ireland, then frankly I'm going to, we'll have to take further steps," he said.
"What we're doing is removing what I think of as the unnecessary protuberances and barriers that have grown up and we're getting the barnacles off the thing and sandpapering it into shape."
Mr Martin said the protocol posed no threat to the integrity of the UK.
"The protocol is not tearing the United Kingdom apart, that's just an overly dramatic presentation of it in our view," he said.
"It explicitly affirms the constitutional position of Northern Ireland and the principle of consent.
"So it's not a danger to the constitutional position of Northern Ireland at all, and was never intended to be."
Speaking on the matter again this morning on his way into a Cabinet meeting, Martin said that it was important to focus on what can be done to reduce tensions.
"We need to work on those and ensure proper dialogue and I'm happy to see that the European Union and the United Kingdom are now engaging in a serious way in relation to resolving issues that have arisen in terms of the operation of the protocol," he said.
"There is still some distance to go, but the only way forward on that is understanding the sensitivities and working to make it as workable as possible for the island of Ireland and that work is underway."
Mr Martin also said that he had been in touch with all the leaders of the political parties in Northern Ireland.