USES AND AVAILABILITY
JUDICIAL review remedies (that is, remedies for breaches of public law) fall into two broad groups. On the one hand are the prerogative orders: certiorari, prohibition, and mandamus;1 on the other hand there are the 'private law' remedies of declaration, injunction, and damages.2 Leaving damages aside, these remedies perform four main functions: the mandatory function of ordering something to be done is performed by mandamus and the injunction; the prohibiting function of ordering that something not be done is performed by prohibition and the injunction; the quashing function of depriving a decision of legal effect is performed by certiorari; and the declaratory function of stating legal rights or obligations is performed by the declaration. The use of more than one remedy to perform two of these functions involves unnecessary duplication and produces undesirable complications in the law.
In its terms an order of certiorari instructs the person or body whose decision is challenged to deliver the record of the decision to the office of the Queen's Bench Division to be quashed (i.e. deprived of legal effect). There is a theoretical problem here because a decision which is illegal in the public law sense is usually said to be void or a nullity in the sense that the decision is treated as never having had any legal effect.____________________