The Planning Service failed to comply with its own policy before giving the go-ahead for an abattoir to operate beside a pharmaceutical research site in Co Antrim, the High Court has heard.
Counsel for the Department of the Environment conceded that a requirement to notify neighbours about Topping Meats' bid to begin slaughtering was not followed.
But despite the oversight, a judge was urged not to overturn the granting of planning permission due to the delay in mounting a legal challenge.
Pharmaceutical giant Warner Chilcott UK, backed by CaridianBCT, a global leader in blood component technology, are seeking to judicially review the move to permit an abattoir.
Both companies have facilities close to the Topping Meats plant on Old Belfast Road, Millbrook, Larne.
As the case went before court, a barrister for the department confirmed the failure to follow requirements under Planning Policy Statement One.
David McMillen said: “The principal point is we didn't comply with our own policy vis-a-vis neighbourhood notification.
“We... didn't consider all relevant matters when coming to our decision.”
He contended that an order quashing the decision was sufficient in the case.