There is a general rule in administrative law that where legislation confers power on a specified individual or authority, it is that individual or authority that must exercise the power, and the power must not be given away to another person or authority (so-called unlawful sub-delegation). This general rule applies to the delegation of all types of power – judicial, legislative and administrative.
However, there are necessarily many exceptions to this rule, which are often set out expressly on the face of the legislation which confers power on the public authority. In other circumstances, the Court will be ready to infer from the wording and purpose of legislation that a particular power conferred on a public authority may be delegated to another person, provided that the authority maintains overall control. The Court will often infer such a power to delegate where not allowing the power to be delegated would lead to disproportionate administrative inconvenience.