The government’s retreat from its hardline position in negotiations with the EU over Brexit arrangements in Northern Ireland has elicited a furious response from the most senior unionist in the House of Lords. Lord Dodds, the former deputy leader of the Democratic Unionist party, has issued a veiled threat of “action” unless it restores the option of pulling the plug on the Northern Ireland protocol by using the article 16 process. “Every day that passes with the protocol in place is another day which sees Northern Ireland and Great Britain move further apart. This is unsustainable. “If the UK government can’t or won’t act, then unionism will and soon,” he said in a statement. He was responding to reports that the UK has dropped its demands for removal of the role of the European court of justice from the Northern Ireland protocol. Downing Street has conceded this week that it will prioritise removing barriers to trade between Great Britain and Northern Ireland over other constitutional issues that have bedevilled the talks. Talks will be suspended until after Christmas. A government source said they would be seeking an “interim” solution on customs and physical checks on food that have proved a barrier to domestic trade and seen 200 businesses stop delivering to Northern Ireland. The change in tack has infuriated Dodds and others including Lady Hoey, who is fighting to get the protocol removed through the courts in Belfast. Dodds said it was now “abundantly clear” that the “protocol talks were being dragged out with little prospect of an outcome which meets the bar” set by Brexit minister Lord Frost’s command paper in July, which laid out the UK’s demands for a radical rewriting of the protocol. He accused the UK of “falling into line” with the EU’s timeline and of “retreating from its commitment to trigger article 16”, despite the prime minister himself declaring “conditions for doing so” were “met long ago”. He also said Frost had pulled back from an earlier negotiating position that all barriers to the supply of medicines from Great Britain to Northern Ireland should be removed. The future of the protocol talks has been further muddied by the shock resignation of a frustrated Frost from the Tory cabinet, revealed on Saturday night. He did not specify what “action” he meant would be taken, but the DUP has previously warned that it would walk out of the Stormont executive if enough progress in the talks were not made by November. In a more nuanced statement issued on Saturday morning, the head of the DUP, Sir Jeffrey Donaldson, said the party had been “patient whilst negotiations have continued”. But “in the absence of the EU’s willingness to agree the removal of the entirely unnecessary barriers to trade on the Irish Sea, it is essential that the government takes decisive action at the beginning of the year to restore Northern Ireland’s place in the UK”. Britain dropped its demand that Europe’s highest court should be removed from the protocol in the past fortnight, accepting there was an option that was acceptable involving the ECJ if disputes fail to be resolved politically or by an arbitration panel. Earlier in the week, Dodds told the House of Lords that the “delicate balance of relationships across these islands have been trashed as a result of the Northern Ireland protocol”.