Q15: What is relevant or irrelevant to the decision?

Your consideration may include factors that must be considered, factors that may be considered, and factors that must not be considered.

The various factors to consider in your decision can be thought about in three ways – mandatory; permissible; or irrelevant considerations.

The factors that must be considered may be expressly stated in the statute or may be implied because their importance is so obvious.

There are three subject-areas which typically raise implied mandatory relevant considerations: 

  • the principles of the Treaty of Waitangi;
  • New Zealand’s international obligations; and
  • human rights.

For example, these may come about due to Māori-Crown agreements or in international treaties.

There will be factors which may be considered and where it is up to the decision-maker to decide whether they are relevant, and how much weight to give them (unless no-one acting reasonably could have taken that approach).

A statute may also expressly state or impliedly require that matters must not be considered and must be disregarded.  These are irrelevant considerations. 

A prisoner successfully argued that a decision not to allow media to interview him was unreasonable.  His right to freedom of expression was an implicit mandatory consideration in the decision whether or not to allow the interview.
Taylor v Corrections [2015] NZCA 477
Section 9 of the Fisheries Act 1996 provides that all persons exercising functions under the Act “shall take into account” certain environmental principles.  This is a mandatory consideration.
A Minister’s decision to decline consent for a marina application was overturned.  By participating in a site visit, the Minister received irrelevant information, even though the subsequent decision expressly said it was disregarded.
Whangamata Marina Society Inc v Attorney-General [2007] NZLR 252
A Minister’s decision to grant a petroleum exploration licence to the Crown, and decline an application by Petrocorp for a licence, was upheld by the Privy Council, notwithstanding the Crown being a party to a joint venture agreement with Petrocorp. 
The Privy Council held that the Minister was right to take the view that the Crown’s contractual obligations were irrelevant and should be ignored.  It was for the Minister alone to identify and determine the national interest, and this decision was not reviewable by the Courts.
Petrocorp Exploration Ltd v Minister of Energy [1991] 1 NZLR 641