Britain said on Wednesday it would not shy away from taking action to resolve post-Brexit trade tensions in Northern Ireland as it rejected European Union proposals to resolve the standoff, in the latest escalation between the two sides.
London and Brussels have been trying for months to break a deadlock over the Northern Ireland protocol, a deal which London struck before it left the bloc and now says is unworkable.
The deal in effect created a customs border in the sea between Northern Ireland and the rest of the United Kingdom to preserve the province's open land border with EU member state Ireland.
British Foreign Secretary Liz Truss said on Wednesday that EU proposals to rethink checks on goods moving between Britain and Northern Ireland failed to address the core problem, "and in some cases would take us backward".
"Prices have risen, trade is being badly disrupted, and the people of Northern Ireland are subject to different laws and taxes than those over the Irish Sea, which has left them without an Executive and poses a threat to peace and stability," she said in a statement.
"The answer cannot be more checks, paperwork and disruption. Our preference has always been for a negotiated solution but (we) will not shy away from taking action to stabilise the situation in Northern Ireland if solutions cannot be found."
Britain wants a full overhaul of the Protocol and has hinted at the possibility of unilaterally suspending part of it if no new deal can be reached - a move that could lead to a suspension of a free trade agreement at a time when inflation is soaring and warnings have grown about a British recession this year.
The increasing rhetoric has already led to alarm in European capitals, with EU negotiator Maros Sefcovic saying on Wednesday that the international treaty was not up for renegotiation.