A court will interfere with an administrative decision or question if it can be shown to go beyond the powers given to the decision maker by Parliament. An administrative action that goes beyond this power is called ultra vires. There is a great deal of case law on the various reasons why a decision may be ultra vires. These are summarised in the following paragraphs.

Irrelevant Considerations- This is the most important ultra vires ground. If it can be shown that a government body, in reaching its conclusions, took into account factors that were not relevant to the matter, or failed to consider matters that were relevant, the court can intervene. In order to decide what is relevant it is necessary to compare the reasons given for the decision or action with those permitted by the Act.

Improper Purpose- This is probably the second most common ultra vires ground. Often, the same factual situation will justify court action on the basis of both irrelevant consideration and improper purpose. Strictly speaking, the claim here is that the decision or action, although on its face proper under the law, is designed to achieve a purpose which is beyond the responsibilities of the government body.

Unreasonableness- A much less readily available ground is to claim that a decision is so unreasonable that no reasonable body would have reached it. This is a difficult ground, because it admits initially that the decision was one that was permissible under the law. What the individual is contending is that it is so unreasonable an application of the law that it goes beyond the inferred limits of the power. Generally speaking, the courts are not inclined to replace their view of hat might be reasonable for that of an outside body, especially an elected body such as a local council.

Bad Faith- To attack an administrative action on the ground of bad faith it is necessary to show that the decision was affected by corruption, bribery or similar malpractice.

Uncertainty - A ground which is rarely available for attacking an administrative action is that it was too uncertain to be meaningful.

No Evidence- This is a relatively recent development in the review of administrative action, as the courts are more prepared now than previously to review decisions where the evidence does not appear reasonably capable of supporting the decision made.

Beyond Jurisdiction- A decision that affects the rights or interests of an individual can be challenged on the grounds that it is beyond the jurisdiction of the decision making body.

Error of Law- Normally, tribunals are free to make legal principles in the field in which they are concerned, but sometimes the law has been decided in other decisions. The tribunal must follow these established principles.

It is sometimes possible to attack a tribunal's decision on the basis that it is obvious from the record of its proceedings or the reason for its decision that it misunderstood some established principle. This is known as an error of law on the face of the record.

Rules of natural justice require that a fair hearing be given and that the proceedings should be free from bias.

The courts have adopted the strict position that a person whose financial interests may be affected by the outcome of the case cannot sit in judgment.

Although the financial interest aspect is clear-cut, there are other situations where a person may be biased; perhaps by being related to someone connected with the case or through having some past professional association with one of the parties, even by having expressed views hostile to those being put by one of the parties.

This type of challenge is not concerned with the reasons given for an administrator's decision or action but with the procedures followed by the administrative body or official in reaching its conclusion. This is an important way of attacking an administrative decision or action. Although the reasons given may be perfectly legal or the action taken clearly within the authority of the administrative body, the law has always insisted that prescribed, or inferred, standards of conduct must be followed by the government in dealing with the community. Anyone wishing to challenge an administrative decision should first look at the Act under which the decision is made to see that the required procedures were followed exactly before the decision was reached. For example:

Any irregularity in following the terms of the Act may be the basis for obtaining judicial review of a decision.

Improper delegation is a narrow ground. Obviously the conduct of government administration requires that ministers, boards and other entities in which responsibility for government decisions is placed must pass over much of their work to subordinate officers. The rule of improper delegation looks at whether or not the person responsible in law for making the decision keeps control over the decision.

Still more unusual are situations where a process is declared legally improper because the decision maker has divested responsibility or acted under dictation. Divesting happens where a decision maker simply gives away her or his authority in a matter. Dictation is where the body responsible for making a decision allows itself to be dictated to by some other entity in the community, normally a person superior in status to that body.

A ground for action may exist where an administrative body applies predetermined guidelines or policy without regard to the merits of the situation.

Although ultra vires claims may be made against any type of administrative decision or action, the principles of natural justice (which from time to time receive a good amount of publicity) do not apply to all administrative decision making situations, but only bind administrative bodies where a judgment is being made which may have the effect of interfering with a significant interest of the individual.

Natural justice must be provided in a wide variety of situations where action is taken against an individual.

In situations where natural justice should be given it is important to read the Act governing the body or official responsible for the decision. Strict procedures are usually set out by the relevant Act. These may include:

The common law rules of natural justice deal with situations where Acts say nothing about what should amount to a fair hearing or have not dealt with an important aspect of the topic, such as legal representation. Often officials such as chief executive officers of government departments are not subject to firm rules, although this is less true of tribunals. The court which reviews a tribunal's actions will compare its procedures with those required by the Act and the principles of natural justice.

Finally, it depends on whether or not a court considers a particular procedure to have been fair in the circumstances and this can vary from case to case. Apart from some fundamental guiding principles, there are no absolute rules in this area and so it is difficult to estimate the chances of success. The matters which most often lead to a finding in favour of a person are: