Judicial Review is the legal avenue for appealing decisions made by public bodies when there is no other alternative mechanism.
It is conducted by the High Courts of Justice Administrative Division.
There is a searchable database of decisions from the High Court Administrative Division at BAILII
CourtServe court listing service
The U.K. Ministry of Justice guide to the Daministrative Courts and Judicial review is attached to this page and it is an indispensable resource for those seeking to challenge Governments - both local and national - including of course - those pesky government "Agencies"