Ameliorating the collateral damage caused by collateral attack in administrative law

Collateral attack is the indirect challenge of administrative decisions, instruments or actions in civil and criminal proceedings for the purpose of determining private rights. Collateral challenges are a common way litigants seek to contest actions of the executive or other public bodies, and represent a different mechanism for the courts to exercise their supervisory jurisdiction over administrative action. The New Zealand courts have adopted a straightforward approach to the doctrine of collateral attack, generally allowing such challenges. This paper explores the principles that underlie the doctrine of collateral attack and the potential difficulties that the doctrine creates. It is argued that the courts should take a more principled approach to determining whether collateral attack should be allowed in any individual case. A number of "touchstones" are proposed to ameliorate any collateral damage to administrative law's unique character while still ensuring that people are able to challenge the invalidity of administrative instruments, decisions or actions as and when they arise in civil and criminal proceedings