Campaigners say they are "deeply disappointed" by a decision by a Belfast court to quash a Stormont decision to approve a huge roads scheme in Northern Ireland.
The High Court ruled in favour of a legal challenge to the £1.2 billion upgrade of the A5 linking counties Donegal to Monaghan through counties Tyrone and Derry.
Niall McKenna of the A5 Enough is Enough group, which has campaigned for the road, said he was deeply disappointed.
He said the decision would add to the anguish of bereaved families.
"We find it ironic the law is there to serve and to protect people and protect the society," he said.
"And the judgment acknowledges that this scheme will have major societal benefits. So it seems ironic, to go against the societal benefits."
An upgrade to the road had been on the cards since 2007 and is a flagship project of the Stormont Executive.
Since the project was first proposed, 57 people have died along the road.
The campaign to have the road redeveloped has been championed by Tyrone GAA, which has its centre of excellence along the existing road and which has lost many members in road incidents over the years.
Former Stormont infrastructure minister John O'Dowd gave the go-ahead for construction last year.
In his findings, the judge said that the road was not mentioned in Stormont's draft Climate Action Plan published last week.
He said this was despite the fact that Northern Ireland might already experience difficulty staying within its first carbon budget, which had just been set in the plan.
He said the environmental impact of the new road had not been properly assessed or scrutinised.
"There was an inadequacy of information for the purpose of lawful decision making and therefore this is yet another reason based in public law for concluding that the decision made in this case cannot stand."
Landowners had challenged approval of the upgrade - an 85km stretch linking Derry to Aughnacloy in Co Tyrone.
They said it would impact homes and farms and breach a Stormont commitment to cut greenhouse gas emissions.
The £1.2 billion scheme would see the road turned into a dual carriageway.
Minister 'extremely disappointed'
Stormont's Infrastructure Minister Liz Kimmins MLA sat through the entire court judgement.
Later she spoke briefly to reporters but said she did not have time to take questions.
She paid tribute to those who had campaigned for the A5 upgrade and said she was "extremely disappointed" by the outcome.
"This is a very detailed judgement and I will have to take time along with my legal team to consider the detail.
"However I'm determined that we will deliver a safer A5 that will protect lives and we will not be giving up in relation to that."
A solicitor for the landowners who had successfully appealed the judgement read out a statement on their behalf.
Ciaran O'Hare said his clients had been vindicated after a 16-year battle against the dual carriageway.
"This isn't just an important day for my clients, this is an important day for the environment."
He said they had never disregarded the safety issues related to the road, but believed they could be addressed with other remedial works rather than a brand new road scheme.
SDLP MLA Daniel McCrossan described the decision as a "bitter blow" for families who have lost loved ones on the road.
"It's not what we expected and has come as a huge shock to the entire community, in particular the families that have lost those loved ones," he told RTÉ's Drivetime.
'Most dangerous road in Ireland'
Campaigners have dubbed it the most dangerous road in Ireland and called for the long proposed work to begin.
The road would be an important link to the entire north west and the project has been promised €600 million in Irish Government funding.
Mr Justice McAlinden ruled in favour of those who had brought the challenge.
He said there had not been sufficient scrutiny of the method of calculating greenhouse gas emissions from the new road.
He also said the human rights of those who had been affected by compulsory purchase orders could be impacted.
Both of these issues needed more work, he said.
He also noted that Stormont's draft Climate Action Plan for 2023-2027 published last week made no reference to the new road.
"I am acutely aware that this decision will bring significant fresh anguish to the doors of those who have been injured and maimed and those who have lost loved ones as a result of road traffic accidents on the existing A5," he said.
"The decision to proceed with the scheme must be taken in accordance with the law and the principle of the rule of law cannot be subverted, even if the motivation for doing so is to achieve what is deemed to constitute a clear societal benefit.
"The shortcomings and shortcuts in the decision making highlighted in this judgment are capable of being remedied."
Ministers should redouble their efforts to deal with the shortcomings so that sooner or later a new and safer A5 dual carriageway may come into operation "and the long list of names of those who have perished on that road will not be added to," Mr Justice McAlinden said.
It is the second time objectors have successfully opposed this road scheme on environmental grounds.
The quashing of the order for the roads scheme will take affect once agreement on its terms has been agreed between the parties.
