O’Reilly v Mackman [1983]

Lord
Diplock:
Reformed
procedure under Ord 53 provided important safeguards for public body.
Hence
would normally be abuse of process to seek declaration or injunction outside
Ord 53.
Where
applicant for JR seeks to protect rights or interests protected only in public law,
must use Ord 53.
[Known
as ‘procedural exclusivity principle’]
Two
exceptions:
1.
Certain types of collateral attack.
2.
Where none of parties objected to remedy being sought outside Ord 53.
Possibility
other exceptions might exist left to be determined on case-by-case basis.