Pressure is mounting on Westminster to take control in Northern Ireland as Stormont's top civil servant said it was unclear what decisions departments here can make without ministers.
David Sterling warned that ongoing uncertainty could put events like this weekend's North West 200 at risk. Fears have grown that the A5 road project and redevelopment plans for Casement Park could be in jeopardy.
The Department for Infrastructure (DfI) yesterday announced it was appealing a High Court decision that its permanent secretary Peter May had no power to give the go-ahead to a controversial incinerator project in Mallusk.
As chaos and confusion reigns over who is running Northern Ireland, unionist politicians said the current state of political limbo could not continue.
Mr Sterling, the head of the civil service, yesterday spoke of the huge implications of the High Court ruling.
"We have got the North West 200 this weekend and road closures for that were signed this year by the permanent secretary of the Department for Infrastructure," he said. "Those road closure orders would normally be signed by a minister.
"So the uncertainty we have is whether it is appropriate for officials to do anything that a minister would normally do.
"If that was the case then we have to question, would it have been possible to run the North West 200 this weekend?"
Northern Ireland has had no local ministers for 16 months since power-sharing collapsed and London is refusing to re-introduce direct rule.
Mr Sterling acknowledged there was no sign of an executive being reformed soon and said civil servants found themselves in an impossible situation.
"We care deeply about the services that we provide to the community," he said. "We should not have to step into the space normally occupied by ministers. We should be operating under the direction and control of ministers. Whilst ministers are (absent) we want to do the best that we can to provide services."
Mr Sterling said civil servants had stepped into the power vacuum with great caution.
"We never expected, or wanted, to have to do this other than for a very short period of time," he said.
"Each decision has been taken on its own merits and senior officials have acted where they believed it was lawful to do so - where it was consistent with the direction of the previous minister or necessary in the public interest that a decision be taken at the time."
The High Court judgment had "potentially wide-ranging implications for decision-making in the ongoing absence of ministers", he warned.
"That is why it is important we obtain greater clarity on the legal position and why it is right for DfI to seek to appeal," he added. It could be months before the appeal is heard.
DUP MP Nigel Dodds yeserday said: "Having no functioning ministers continues to cause havoc for people living here. Civil servants are trying to run Northern Ireland but in many cases big decisions and reforms are being left in limbo.
"Four out of the five main parties would fully restore the executive today. Sinn Fein have no interest and have checked out of decision-making.
"Sinn Fein may not like ministerial decisions being made in London but if they continue to block devolution then there are very few alternatives."
Ulster Unionist leader Robin Swann called on the government to intervene immediately.
"We agree with David Sterling that decisions should be taken by democratically-accountable ministers," he said.
"It is now time for Secretary of State Karen Bradley to step in and take a grip of this.
"It is totally farcical that civil servants are having to challenge a legal decision in order to provide clarity on what decisions they can make as they have been left adrift and without leadership."
Mr Swann continued: "If the Secretary of State cannot provide a clear pathway that sees the devolved institutions restored with local parties at the helm, then she must move to appoint UK government ministers."
SDLP MLA Mark Durkan said Mr Sterling's statement set off "alarm bells that signify the dangerous position Sinn Fein and the DUP have led us in to".
He continued: "The SDLP have been consistently clear, that in order to resolve the ambiguity around these concerns, the British Government must convene the British-Irish intergovernmental Conference to agree a deal and bring forward a package of legislation to ensure Northern Ireland isn't left in limbo."
Mr Durkan said the SDLP would continue to support residents who opposed the incinerator plan.
Sinn Fein chairman Declan Kearney expressed his disappointment that the DfI was appealing the High Court ruling which he said had been in "the public interest and the interest of Hightown residents' safety".
He added: "This decision to appeal by the department runs counter to that public interest.
"Once again the DfI are on the wrong side of this issue. It should belatedly accept that fact and comply with the High Court judgement."
In her ruling on Monday overturning the DfI's decision to give the go-ahead to the Mallusk incinerator, Mrs Justice Keegan said that, despite the absence of an assembly and minister, a decision should still have been made by a minister and not civil servants.
Planning permission for the waste facility had been approved last September but strong objections from local residents continued. Planning approval for the A5 has been granted but a legal challenge to Northern Ireland's biggest road project is due to be heard soon.