When a court declares administrative conduct (such as a tender award) invalid under section 172(1)(a) of the Constitution, it must then consider whether to grant a just and equitable remedy under section 172(1)(b). Even where a tender is void ab initio, it is just and equitable to order payment for services rendered and received where: (a) the service provider is not at fault for the invalidity; (b) the beneficiary received full value from the services; (c) the beneficiary did not dispute the quality or receipt of services; (d) the service provider incurred expenses in rendering the services; and (e) the beneficiary advanced no valid reason against payment. The remedy must fit the injury, be fair to those affected, vindicate the rights violated, and be just and equitable in light of the facts, constitutional principles, and controlling law. Payment can be ordered equivalent to what would have been due under the void contract, even though the contract itself cannot be enforced.