Judgment was reserved today in a second legal challenge to a multi-million pound dual carriageway project linking Counties Derry and Tyrone.
A campaign group opposed to the A5 scheme claimed in the High Court it should be halted over a failure to carry out a strategic environmental assessment (SEA).
They also contend there has been a procedural flaw in requirements to consider need, justification and other options to the planned new 85km route.
But Attorney General John Larkin QC, representing the Department for Infrastructure, describing the arguments advanced as “absurd”.
Work on the new dual carriageway section is due to get underway next year.
In 2013 a group of farmers, landowners and supporters known as the Alternative A5 Alliance won their first legal action against the new Derry and Aughnacloy, Co Tyrone road.
At that stage a judge quashed the decision to press ahead with the scheme, which forms part of a proposed key cross-border business route linking Dublin and the north west, due to a breach of a habitats directive.
Lawyers representing the Alliance have now returned to court to seek a judicial review of renewed plans.
They argued that the project must be subject to an SEA if it features in Stormont’s next Programme for Government.
Mrs Justice Keegan was also told there is a requirement for alternatives to be properly considered at an ongoing public inquiry.
Greg Jones QC claimed anything less would render the process academic.
“The public inquiry should not be engaged in what is no more than a sixth form debating society exercise,” he said.
He alleged a failure to define what will then come under relevant considerations.
“Its a charade if it’s not subsequently taken into account by the Department,” Mr Jones added.
But Mr Larkin responded by stressing a further hearing next month will examine alternatives and enable objections to be voiced.
“That’s not only a knock-out blow, that’s a pulverising blow as far as that raft of arguments is concerned,” he said.
The Attorney General also emphasised that nothing more than a draft Programme for Government currently exists.
The Stormont Executive must agree on it, and the Assembly approve it on a cross-community basis before it can come into force, the court heard.
But Mr Larkin confirmed: “There’s going to be nothing in the Programme for Government about the A5, directly or indirectly.”
Describing the legal challenge as premature, he added: “This case is, with respect, frankly absurd.
“There’s no Programme for Government, the (inquiry) is giving objectors everything they want and the Department will have to look at that.”
Following submissions Mrs Justice Keegan reserved her decision on whether to grant leave to seek a judicial review.
She said: “This is obviously an important case. I will take some short time to determine this leave application.”