A bargaining council established under the Labour Relations Act does not exercise 'public powers' or perform 'public functions' when procuring services for projects funded by its members, even where the underlying collective agreement has been extended by ministerial declaration. Such procurement decisions constitute domestic functions for which the council is accountable to its members, not to the public, and therefore do not constitute 'administrative action' subject to review under PAJA. The test for whether conduct is subject to public law review requires examining whether the function has features that are 'governmental' in nature, considering factors such as: integration into governmental regulatory systems, governmental supervision and regulation, public funding, substitution for governmental functions, and public accountability. Procurement by bodies using member contributions (as opposed to public funds) does not attract the public accountability required by s 217 of the Constitution or PAJA. A legitimate expectation of procedural fairness does not arise merely from responding to an invitation to tender; it requires an express promise or regular practice that objectively gives rise to a reasonable expectation of a hearing. Where concerns are raised and parties given opportunities to address them, no further hearing is required before rejecting proposals.