Good Decision-Making For Public Bodies, Guide 2: Three Fundamental Principles

Author:Ms Joanelle O'Cleirigh and Roberta Guiry
Profession:Arthur Cox

This is the second in our new series of Good Decision-Making Guides for Public Bodies. These Guides highlight what is best practice in decision-making and offer simple and practical tips to reduce the risk of challenge to your decisions.


There are three fundamental principles of good decision-making that decision-makers in public bodies must always have in mind when making decisions.

The decision-making body must:

i. have the legal power to make the decision.

ii. have regard to any relevant factors and exclude any irrelevant considerations.

iii. make a rational decision.

In this Guide we look at each of these principles.


    The decision-making body must have the legal power to make the decision. If it does not, it will be acting beyond its powers (or ultra vires) and the decision will be invalid.

    The power to make a decision may be:

    Express: set out in primary legislation (statutes) or secondary legislation (orders, rules, regulations, bye-laws). For example, the Central Bank (Supervision and Enforcement) Act 2013 gives the Central Bank an express power to "give a direction in writing to [a] regulated financial service provider... to take [specified] actions." Implied: a power will generally only be implied where (i) it is justified by the statutory context; (ii) it is not of such a nature that you would expect to see it set out specifically; and (iii) it is consistent with the statutory scheme (see example below). Incidental: a power to do whatever is incidental to or consequential upon specific statutory powers. The extent of these powers will depend on the general policy underlying the legislation in question. For example, the Personal Injuries Board Assessment Act 2003 gives the Injuries Board "all such powers as are necessary or expedient for, or incidental to, the performance of its functions under this Act." EXAMPLE:

    The Commission to Inquire into Child Abuse sought to limit the number of legal representatives who could be present during evidential hearings to one solicitor and one barrister per party. It did not have an express power to do this under the Commission to Inquire into Child Abuse Act 2000.

    The Commission argued that the power was implied and incidental to the obligation imposed on it under the Act to conduct evidential hearings "in an atmosphere that is as sympathetic to, and as understanding of, [victims] as is compatible with the rights of...

To continue reading