The DUP have withdrawn from a meeting of the Northern Ireland Grand Committee at Westminster.
The Northern Ireland Grand Committee sits at Westminster
Party chief whip Nigel Dodds said as the committee never sat in Northern Ireland his party would not be participating in the meeting.
The Welsh and Scottish Grand Committees sit in their respective countries.
All 18 NI MPs are entitled to sit on the Northern Ireland Grand Committee, which debates matters specific to the province.
In addition, there are 25 MPs from the Labour, Conservative and Liberal Democrat parties entitled to sit on the committee.
In the past, the DUP has accused the SDLP of vetoing meetings of the committee being held in Northern Ireland.
Mr Dodds called on the government to act to overcome the "veto".
He said the DUP would be keeping its position in regard to further meetings in reserve until the party knew what action was going to be taken by the government.
"We have had promises and assurances in the past about the Northern Ireland Grand Committee," he said.
"Bizarrely and amazingly, it has never met in Northern Ireland and it is about time this anomaly and absurdity is rectified.
"We have raised this on countless occasions with the secretary of state, in the House of Commons and elsewhere."
The SDLP criticised the DUP for walking out of the committee.
SDLP leader Mark Durkan said his party was not opposed to the committee meeting in Northern Ireland.