ABSTRACT
Protection of the interests of individuals affected by the exercise of practical powers must be a matter of public law since those individuals cannot seek protection by insisting on their private law rights. When a core public authority exercises private law-type powers, we must therefore think of it as simultaneously subject to two sets of norms, those of private law and, at the very least, the purpose-regarding norms of public law. From the view of public power as always restricted by reference to public purposes important consequences follow. One consequence concerns those powers that core public authorities hold in common with private persons. A core public authority may possess the capacities and powers of a private person. One might contrast the authoritys conduct in these street or market trading cases with other harm-causing exercises of a public authority landowners powers in relation to which it would be unnecessary to invoke public law norms.
