Brexit minister Lord Frost has said the UK will not sweep away the Northern Ireland Protocol as he warned conflict over the deal risks creating "cold mistrust" with the European Union.
The negotiator of the post-Brexit agreement renewed calls on Saturday for Brussels to accept a "substantial and significant change" to the deal.
Northern Ireland is effectively kept in the EU's single market for goods by the protocol, which prevents a hard border with Ireland but has created trade barriers with Britain.
Unionists have pressured for the abolition of the protocol, but Brussels has repeatedly rejected the UK Government's plea to negotiate it.
Speaking at the British-Irish Association conference in Oxford, Lord Frost said: "The stakes are high. The arguments can be bitter.
"And I worry this process is capable of generating a sort of cold mistrust between us and the EU which could spread across the relationship.
"It's holding back the potential for a new era of cooperation between like-minded states in a world which needs us to work together effectively."
The Tory peer reiterated the UK's position that the "threshold" for triggering Article 16 to effectively tear up parts of protocol has been met.
But he added: "Some would like us to sweep all the existing arrangements away. That is not our position.
"It is obvious there will always need to be a dedicated UK-EU treaty relationship covering Northern Ireland. It is a question of finding the right balance."
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