This is the fifth in our 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.

In this Guide, we look at:

  • the principle of proportionality;
  • the exercise of discretion in decisionmaking; and
  • how to use policies/guidelines properly.


A decision may be challenged on the ground that it is disproportionate, i.e. the effect of the decision is disproportionate to the intended objective.

Proportionality generally comes into play when looking at the `reasonableness' of a decision. As discussed in Guide 2, a decision will be unreasonable where it plainly and unambiguously flies in the face of reason and common sense. If a decision is unreasonable, it may also be disproportionate.

When considering the proportionality of a decision, look at the nature of the decision and the decision-maker. Take particular care where constitutional or European Convention rights are concerned. Remember, you do not need a sledge hammer to crack a nut.


In 1999, the applicant was appointed as principal of a vocational school. Between 2001 and 2003, three complaints were made about the way in which she managed the school. In 2005, the Minister for Education directed that an inquiry be established to investigate this. In 2011, after considering a report prepared by the head of the inquiry, the Minister decided that the applicant should be removed from her post.

Held: The Minister's decision was manifestly disproportionate. The applicant was appointed to the role at a time when the school was facing a number of challenges, including falling enrolment numbers. The three complaints that had been made against her involved events that occurred when she was relatively new to her role. By the time the Minister decided to remove her from office, these complaints were 8-10 years old. The report furnished to the Minister showed that the applicant had since been performing very well in the role. (McSorley v The Minister for Education and Skills)


Decision-makers may have to exercise discretion when making decisions. They may have a choice about whether or not to do something, for example whether to approve an application, impose a sanction, provide a particular service, etc. We touched on this in Guide 2 when we discussed the obligation on decisionmakers to take account of relevant factors and the need to distinguish between factors that must be taken into account (mandatory factors) and factors that may be taken into account (discretionary factors).

To ascertain whether you have discretion, go back to the source of the decision-making power, usually the legislation. If the legislation states that you "shall" or "must" do something or do something in a particular way, this will usually mean that you no discretion.

For example, if the legislation states that a complaint must be determined by a committee made up of certain specified people, then only those people may determine the complaint. If the legislation does not specify precisely who should sit on the committee, you may have some discretion here.

The exercise of discretion requires the exercise of good judgement.


The general rule is that a power must be exercised by the individual or body in which it has been vested by legislation. However, this is not always possible in practice and a number of exceptions have been recognised.

Government ministers

Government ministers cannot personally exercise all the duties and powers that have been vested in them by legislation. Responsible officials in their departments may act on their behalf. Ministers do not have to specifically delegate authority, but the official who exercises their duties or powers must be of the appropriate level

and seniority. Importantly, ministers remain responsible for decisions made by their officials.

This exception is known as the Carltona principle. It is not an absolute rule; in cases of significant public importance, ministers may be required to exercise certain powers personally.


An assistant principal officer in the Department of Justice refused a couple, who had breached the terms of their entry conditions, permission to remain in the State. She did not consult the Minister before making her decision. The couple argued that the official had no authority to make the decision and that the decision could only be made by the Minister personally.

The relevant legislation specifically vested the power to refuse permission to remain in the State in the Minister for Justice.

Held: The legislation vested extensive powers in the Minister for Justice. It could not have been the intention of the Oireachtas (the legislature) that the Minister should personally exercise these powers. The assistant principal officer who made the decision had particular responsibility for the immigration and citizenship division of the Department. In making the decision, she was acting on behalf of the Minister. (Tang v Minister for Justice)

Statutory authority to delegate

Legislation may provide for a specific delegation of power. For example, the Personal Injuries Board Assessment Act 2003 states that the Injuries Board may delegate its functions in relation to the employment of staff and the determination of selection procedures to its chief executive.


  • Before you delegate the power to make a decision, confirm that you have the power to do so. Check the relevant legislation.
  • Ensure the decision is one that can be delegated.
  • Only delegate to someone of the appropriate level and seniority.
  • Ensure that the person to whom you delegate will make the decision in a fair and reasonable manner.


Policies and guidelines can assist decisionmakers in the exercise of their discretion and can also help to ensure that decisions are made in a consistent and fair manner.

However, a policy or guideline should not interfere with or `fetter' the discretion of the decision-maker. The decision-maker must remain free to exercise his own independent judgement and to consider each case on its own merits.


The applicant, a registered firearms dealer, applied to the Minister for Justice for an occasional licence for a double barrel .47 calibre rifle. The Minister refused to grant the licence, stating that it was not "current policy" to grant firearms certificates for rifles of that type. The applicant challenged this decision, arguing that the Minister had adopted a rigid and inflexible policy and had unlawfully fettered his discretion.

Held: The decision was "infected by the vice of inflexibility". Where a statute confers a discretionary power, the decision-maker must exercise that discretion properly in each individual case. A decision-maker cannot lay down a rigid policy from which he does not allow himself to depart. The Minister did not offer the applicant an opportunity to address the possibility of an exception to the policy or the merits of the particular firearm. (McCarron v Kearney)

This case shows the importance of exercising discretionary statutory powers appropriately. It also shows that a failure to exercise a discretion at all, for whatever reason, can leave you open to challenge. If you adopt an inflexible position and adhere to it so rigidly, it may be said that you did not apply your mind to the decision at all and that you abused your statutory discretion.



  • Draft the policy/guideline in plain, simple English. This will help ensure that all staff apply and interpret it consistently.
  • Make sure that the policy/guideline is consistent with any relevant legislation.
  • Set out the purpose of the policy/ guideline at the start.
  • State that the policy/guideline is not to be applied rigidly to all cases and that decision-makers must evaluate the merits of individual cases.
  • Make sure that all members of staff are aware of the policy/guideline and understand how it should be applied.
  • Make the policy/guideline available to the public.


  • Direct your mind to the facts of each case and consider each case on its merits. Make it clear that you have done so by the terms of your decision.
  • Make sure that the person who will be affected by your decision is aware of the existence of the policy/guideline and that you will be referring to it when making your decision.
  • When giving reasons for making your decision, refer to the facts of the case and any policy/guideline you relied on in reaching the decision. Referring only to the policy/ guidelines without mentioning the facts of the case is not enough.
  • Do not depart from a policy/ guideline without giving an explanation. If your organisation has a policy/guideline in place, people are entitled to expect that decisions will be made in accordance with it.


In our next Guide, we will look at what you can expect if a decision you make is judicially reviewed.