The case confirms that res judicata, issue estoppel and Anshun estoppel apply to bar repeated challenges to the validity of town planning schemes where the substance of the challenge has been previously determined or could and should have been raised in prior proceedings. A party challenging the procedural validity of a delegated legislative instrument bears the onus of adducing evidence in proper form to establish that procedural steps were not properly taken. An appellate court finding inadequate reasons below may determine the matter itself rather than remitting it.
The full text is available to signed-in members, including the 9 later cases that cite this judgment.