Categories of Illegality

Simple Illegality

Errors of Fact

Retention of Discretion

Abuse of Discretion

Errors of Law

The term ‘ultra vires’ is often used as a generic phrase relating to any decision which is tainted by illegality (e.g. a police officer arresting a person for parking on a yellow line, when there is simply no power of arrest in such a situation).

The decision-maker makes a mistake concerning a question of law. For example, it misinterprets the meaning of a statutory power.

Where the decision-maker acts 'outside the four corners of the Act'.

Exceptions to reviewability of errors of law:

  1. Where the error of law is not decisive to the decision - by 'decisive', it is meant that, but for the error concerned, the decision would have been different.
  2. Where the decision-maker is interpreting some special system of rules, courts are often unwilling to intervene, for example, with statues of an old university.
  3. Where the power granted is so imprecise that it is capable of being interpreted in a wide range of different ways, the courts will not necessarily quash a decision just because they would have come to a different view.
  1. Precedent Facts:
    Where a decision-maker's power to decide on a particular matter (i.e. its jurisdiction to do so) depended on it making an initial finding of fact (White and Collins / ex p Khawaja).
  1. No Evidence for a Fact:
    If a finding of fact, on which a decision is based, is supported by no evidence at all, the courts have felt able to overturn a decision based on it (Coleen Properties).
  1. Ignorance or Mistake of an Established Fact:
    An established fact, which is material to the decision, is ignored or misunderstood.
    For this to be reviewable, it must have given risk to unfairness. There is a four-part test (E v Sec of State for Home Dept):
  2. There must have been a mistake as to an existing fact, including a mistake as to the availability of evidence on a particular matter.
  3. The fact or evidence must have been 'established' in the sense that it was uncontentious and objectively verifiable.
  4. The appellant (or his advisors) must not have been responsible for the mistake.
  5. The mistake must have played a material (not necessarily decisive) part in the tribunal's reasoning.

Concerns the decision-maker misusing their statutory power in one of the following ways:

  1. Failing to take relevant consideration OR taking an irrelevant consideration into account
    There are three kinds of considerations (ex p Fewings):
    a) those clearly identified by the statute as considerations to which regard must be had ("mandatory factors")
    b) those clearly identified by the statute as considerations to which regard must not be had ("prohibitory factors")
    c) those to which the decision-maker may have regard if in his judgement and discretion he thinks it right to do so ("discretionary factors")
  1. Using the power for an improper purpose
    A decision-maker should only use a power given to it by Parliament for the purpose for which it was given.

If given discretionary powers, decision-makers must exercise that discretion and not ‘fetter’ or restrict themselves. This ground mainly arises in one of two ways:

  1. Fettering of Discretion:
    A public body is seen to have ‘fettered’ its discretion when it has acted in a way that hampered its own ability to properly exercise a discretionary power.
    One way in which this can arise is where the public body decides not to consider exercising a power at all (ex p Fire Brigades Union).
    The courts will not allow a decision-maker to bind/fetter its discretion by adopting a rigid or blanket policy, so that the outcome of a particular case is decided in advance, or without proper exercise of discretion in response to individual factors.
  1. Unlawful Delegation of Discretion:
    Where a public body is empowered to make a decision by an Act of Parliament, the general rule is that a decision-maker is not normally allowed to delegate that discretion to someone else.
    Some statutes will expressly allow the decision-maker to delegate decision-making powers to someone else.
    The Carltona Principle - In central government, the minister may delegate his/her discretion to officials (civil servants) within the department. Where decision making is delegated, power should be delegated to someone of appropriate seniority and accountability.

Old position - only jurisdictional errors of law were reviewable (i.e. where a public body made a mistake about whether it had any legal authority to decide on a matter).

New position - post Anisminic [1969] and ex p Page [1992], all errors of law are now reviewable.

  • Where decision-maker has misunderstood one or more facts or circumstances regarding the case or the claimant.
  • They are generally not reviewable because generally it is down to the original decision maker to consider the facts of a case. Except in the following three situations: