SDLP leader Colum Eastwood has called for representation on the Joint Ministerial Council to be extended in the absence of a Stormont executive.
The Foyle MLA has written to British Prime MInister Theresa May calling for the north's five main his party to be given places on the devolved administrations' forum.
He said such a move was necessary due to the continued political stalemate and the "unique challenges" posed by Brexit.
“It is utter madness that while the Brexit negotiations are taking place, the voice of the majority of people in the north of Ireland who voted to remain is silenced," Mr Eastwood said.
“With the Joint Ministerial Council set to meet next month, I’ve written to the British prime minister today to demand that in the absence of an assembly and an executive, representation must be given to all five major parties in Northern Ireland."
The SDLP leader said it was "not acceptable" that the pro-Brexit DUP were the only party representing the views of the north, as Arlene Foster's party did not represent the majority of the region's people.
"While we in the SDLP are working with Labour and the SNP in Westminster, as well as with our colleagues in Europe and Ireland, the British government needs to get it’s head out of the sand to start real meaningful engagement with all parties here in the north – a seat at the Joint Ministerial Council would be a start," he said.
