Northern Ireland's biggest ever road project could be the next victim of a court judgment that questioned the ability of officials to make major policy decisions in the absence of devolution.
The A5 Western Transport Corridor was approved by the Executive more than 10 years ago, but has been delayed by a series of legal challenges.
The latest case will be heard in just over a fortnight, with the bill for the taxpayer expected to be over £350,000.
Yesterday, parties voiced concerns over the scheme's future in the wake of a High Court judge blocking a decision by a senior civil servant to approve a huge waste incinerator plant at Mallusk.
SDLP MLA Daniel McCrossan has slammed the A5 case as an "unnecessary waste of money".
He said the decision over the incinerator "called into question the validity of any decisions made by the Civil Service during the political impasse and this is why it is essential that we get clarity about the future of the A5".
He said: "It is absolutely imperative that there are no more delays in this critical infrastructure project after years of broken promises and non-delivery. Therefore, the only solution to ensure the delivery of this project is for politicians to get back to work."
Mr McCrossan said he still believed that the first phase of the scheme from Newbuildings to Strabane would go ahead, as it had received ministerial sign-off by the previous Executive.
He was speaking after the Permanent Secretary of the Department for Infrastructure (DfI)wrote to him to say that he does not "expect any impact on the ability to complete that section of the A5". However, last night a DfI spokesperson was unable to give reassurances about the future of the flagship project. "The department continues to consider the wider implications of Monday's judgment," they said.
Alliance leader Naomi Long said she had concerns about the A5, saying the ruling "raised a significant challenge to the lawfulness of decision-making by the civil service in the absence of devolved institutions. There are a number of key infrastructure projects, the progress of which could be jeopardised by the implications of yesterday's ruling, including the A5 Western Transport Corridor and the North-South interconnector."
"The Secretary of State needs to urgently appoint an independent facilitator to reconvene all-party talks as soon as possible and pursue agreement from all to have Assembly committees sit, in order to scrutinise and advise departments on key decisions and policy, taking forward legislation on issues," she said.
Ulster Unionist MLA Rosemary Barton also warned that the Government needs to act following the "very significant" ruling which threatens many projects. "Either through the Secretary of State introducing direct rule or making a renewed effort to get all-party talks started immediately," she said.
However, a Sinn Fein spokesperson said the A5 is "a very different scenario" to the Arc 21 incinerator project as it was granted approval by former DfI minister Chris Hazzard before the institutions collapsed.
They said there was "absolutely no reason" why construction of the 85km road should not proceed following the resolution of the pending court case.
A Government spokesperson said the Secretary of State is considering the High Court judgment on the incinerator.