A major road project in Northern Ireland faces further delay due to concerns over flood risk and environmental impact.
The A5 connects Co Derry to the Irish border at Aughnacloy.
Upgrade work is intended to improve access to Dublin and an investigation found it would benefit journey times and economic competitiveness.
The Planning Appeals Commission (PAC) said: “I have found that the scheme would have large adverse effects on climate, on the landscape and on certain local communities; and that it would have significant adverse effects on the cultural heritage, on flora and fauna, on human beings by reason of noise and vibration, and on material assets.
“I have also found that more work is required on the habitats assessments to ascertain that no reasonable scientific doubt remains that the scheme would not adversely affect the integrity of any designated nature conservation site of European importance.”
It said it may be possible for the Infrastructure Department to rectify the defects.
The report added: “The scheme is dependent upon large-scale compulsory acquisition of land.
“It would interfere with rights and freedoms guaranteed under the European Convention on Human Rights, namely the right to respect for private and family life and the right to the peaceful enjoyment of possessions.
“These are, however, qualified rights and interferences may be justifiable provided it is shown that there is a compelling case in the public interest.”
The report said the flood risk assessment did not take account of recent floods.
It added: “I can only conclude that it is not policy compliant or fit for purpose.”
Infrastructure Minister Nichola Mallon said the A5 was a priority as a strategic road.
She added: “It will open up connectivity in the North West and the rest of our island, ensure safer travel for communities and deliver opportunities for our local economy.
“I know this project has been long awaited and I am determined as minister to see it progress through the statutory process as quickly as possible, ensuring the project is delivered properly for citizens and our wider environment.”
The PAC has made recommendations which were published on Tuesday.
Ms Mallon said: “I have accepted the commissioner’s key recommendation regarding the preparation of and consultation on further documents on the important topics of flood risk and the consideration of alternatives to the proposed scheme.
“As such, I have asked officials to prepare a further addendum to the environmental statement for consultation in early autumn.”
She added: “While I anticipate this approach will lead to the re-opening of the public inquiry, as recommended by the PAC, early next year, it will enable it to consider further public representations made on the two key topics of flood risk and scheme alternatives and prepare its final report.
“This, in turn, will allow a decision on the next steps for this important transformative scheme.”