In City of Edinburgh Council v Secretary of State for Scotland  1 WLR 1447, 1458 E-F Lord Clyde explained the operation of this principle:
“If the application does not accord with the development plan it will be refused unless there are material considerations indicating that it should be granted. One example of such a case may be where a particular policy in the plan can be seen to be outdated and superseded by more recent guidance. Thus the priority given to the development plan is not a mere mechanical preference for it. There remains a valuable element of flexibility.”
** Applications for planning permission are required to be determined in accordance with the statutory development plan unless material considerations indicate otherwise (s.38(6), Planning and Compulsory Purchase Act 2004).