A court has dismissed an appeal over planning permission that was granted for a £240 million waste incinerator.
The Court of Appeal held today that only the full Executive could authorise the proposed facilities on the outskirts of north Belfast because they were so significant, controversial and cut across areas of responsibility.
Arc21, the firm behind the incinerator, said it was "disappointed" by the court's decision.
In May, a High Court judge ruled that a senior civil servant did not have the power to grant planning permission for the incinerator at Hightown Quarry in Mallusk.
The decision had been made by the permanent secretary of the Department for Infrastructure in the absence of a minister.
There have been no ministers in post in Northern Ireland following the collapse of Stormont in January 2017.
The north's government departments have since been led by senior civil servants.
The Department for Infrastructure appealed against the High Court verdict in a bid to provide clarity over civil servants' powers to govern following the collapse of devolution.
They argued that the British Parliament anticipated periods where Northern Ireland would have to be run without a functioning Executive in place.
But in a ruling issued this morning, the Court of Appeal denied that appeal.
It concluded that the decision made by the department was "crosscutting, significant and controversial", and "therefore, a decision which could only be taken by the Executive Committee".
A spokesman for Arc21 said: "This is a disappointing ruling that Arc21 and its stakeholders will now review."
TUV leader Jim Allister said the decision shows direct rule must be imposed.
"Today's Court of Appeal judgement leaves little hiding place for our dithering Secretary of State," he said.
"To meet the UK Government's responsibility to give government to all of the Kingdom she needs to now move forthwith to Direct Rule, given she hasn't the bottle to amend the NI Act 1998 to provide for a workable form of devolution.
"Stormont is clearly not going to give us government, so Westminster must."
Ulster Unionist leader Robin Swann urged the Secretary of State to either restore some form of devolution or introduce direct rule.
"She can no longer remain a back seat driver and must move to restore some form of devolution or the Government should appoint direct rule ministers on Monday," he said.
"There is no running away from this. It is a time for decisive leadership."
North Belfast MLA Nichola Mallon said the incinerator should never have been approved in the first place.
"Our message to the Department for Infrastructure is to not waste anymore public money by pursuing this further to the Supreme Court," she said.
"Our hospitals and schools are crying out for investment, for the Department to continue with trying to defend the indefensible through the courts would be a gross waste of badly needed public money.
She added: "We urgently need a local Executive with democratically elected and accountable local ministers to take decisions in the interest of the people of Northern Ireland".
Sinn Féin MLA Declan Kearney said the department should withdraw its "support for permission to proceed with this incinerator".
"The Court was very clear that it would be contrary to the Good Friday Agreement for such a significant and controversial decision to be taken by departmental officials in the absence of an Executive," he said.
"I very much welcome that as it again signals the importance of re-establishing the power-sharing institutions in a way that is consistent with the Good Friday Agreement."
