The Democratic Unionist Party’s leader has warned she will not back any plan for Northern Ireland to adopt European regulations after Brexit.
Arlene Foster told her party’s conference she wanted a “sensible Brexit” with a seamless Irish border, but said Northern Ireland could not operate under different rules to the rest of the UK.
The border is one of three issues Brussels wants progress on in the next 10 days before it decides to move on to Brexit trade talks.
The Irish government has demanded that Britain put in writing how it plans to make good on a commitment to the 310-mile (500km) border remaining frictionless before it will sign off on the first phase of negotiations.
Dublin and EU officials say the best way to avoid a “hard border” is to keep regulations the same north and south.
But the DUP, which is propping up Theresa May’s minority government, rejects the idea.
Ms Foster told delegates: “We will not support any arrangements that create barriers to trade between Northern Ireland and the rest of the United Kingdom or any suggestion that Northern Ireland, unlike the rest of the UK, will have to mirror European regulations.
“The economic reality is that our most important trading relationship is with the rest of the United Kingdom and we will do nothing that puts that at risk in any way.”
The DUP has so far not presented a solution that would resolve the differences between Britain and the European Union on the border.
The former Stormont first minister got a rousing reception from Union flag-waving party faithful at the DUP’s first conference since it became the political kingmaker at Westminster.
She warned Sinn Fein to “get serious” about the terms of a deal to restore devolution, 11 months on from its collapse.
Foster said she believed devolution was still the best way to govern the region but her deputy leader, Nigel Dodds, warned the moment was fast approaching when a return to direct rule from London “will be the lesser of two evils.”