A group advocating the provision of a Children's Hospital at the Mater site in Dublin has said it is shocked the development will not go ahead.
The Children in Hospital Ireland group said it will have "a profound negative impact" on the delivery of healthcare for children.
CEO Mary O'Connor expressed surprise and dismay at An Bord Pleanala's decision and said it means a new hospital will not be available for sick children and their families for many years to come.
The decision comes just a day after the Irish Association for Emergency Medicine warned that overcrowding is at a historical high and dangerous level in Paediatric Emergency Departments with children requently spending between 12 and 24 hours on a trolley waiting for admission.