Judicial review in the UK is the legal mechanism by which the High Court supervises the lawfulness of decisions made by public bodies in England and Wales. It is not an appeal on the merits. Instead, the court examines whether a decision was made lawfully, fairly, and within the powers granted by Parliament.
Judicial review plays a central constitutional role in upholding the rule of law. It ensures that ministers, regulators, local authorities, and other public decision-makers act within legal boundaries.
However, it is procedurally demanding, tightly filtered at the permission stage, and carries significant costs risks. Understanding how it works in practice, including when it succeeds and when it fails, is critical for practitioners and claimants alike.
What is Judicial Review UK?
Judicial review UK applies where a public body is exercising a public function, and its decision is alleged to be unlawful. It is generally available only where there is no adequate alternative remedy, such as a statutory right of appeal, and where the claim is brought promptly.
The jurisdiction extends to decisions made by government departments, local authorities, regulatory bodies, immigration decision-makers and, in appropriate cases, public appointment processes. The defining feature is not the identity of the decision-maker but the public nature of the function being exercised.
Importantly, judicial review does not allow the court to substitute its own decision for that of the authority. The court’s role is supervisory rather than appellate. It examines legality, not the merits of the outcome.
The procedure for Judicial Review UK
Pre-action protocol
Before issuing proceedings, a claimant will ordinarily send a pre-action letter setting out the decision under challenge, the legal grounds relied upon, and the remedy sought. This stage serves both procedural fairness and efficiency, giving the public body an opportunity to respond and, in some cases, reconsider its position before litigation is commenced.
Time limits
Judicial review claims must be brought promptly and, in most cases, within three months of the decision being challenged. The requirement of promptness operates independently of the three-month limit, meaning that delay can defeat a claim even if it is technically within time.
Certain areas are subject to shorter deadlines. Planning challenges typically must be issued within six weeks. Public procurement claims often operate under even tighter timetables. Immigration judicial review is governed by specialist procedural rules and frequently involves urgent applications. Delay is frequently fatal to a claim.
Permission stage
Judicial review is tightly controlled by a permission filter. At this stage, the court considers whether the claim is arguable and whether it has a realistic prospect of success. Many claims do not progress beyond this preliminary stage. The permission requirement reflects the court’s role in balancing access to justice with the need to prevent unmeritorious challenges from disrupting public administration.
Substantive hearing
If permission is granted, the case proceeds to a full hearing where the court considers detailed legal submissions and evidence. The focus remains on legality rather than merits. If the claim succeeds, the court may grant an appropriate public law remedy, but it will not substitute its own decision for that of the original decision-maker.
Grounds for Judicial Review UK (with explained case examples)
Judicial review UK is not concerned with whether a decision was “right” or “wrong” on its merits. Instead, it examines whether the decision was lawful. The recognised grounds fall into four principal categories: illegality, procedural unfairness, irrationality, and proportionality.
Illegality
Illegality arises where a public authority exceeds its legal powers, misinterprets legislation, or acts outside constitutional limits.
Example: R (Miller) v Secretary of State for Exiting the European Union [2017] UKSC 5
What happened?
Following the 2016 Brexit referendum, the Government sought to trigger Article 50 using prerogative powers without parliamentary approval.
The legal issue:
Could the executive remove statutory rights created by Parliament without parliamentary authorisation?
The Supreme Court’s decision:
No. The Court held that leaving the European Union would remove rights created under the European Communities Act 1972. Only Parliament could authorise such a change. The Government had acted beyond its constitutional authority.
Why this matters:
This case confirms that judicial review UK can restrain executive overreach where constitutional principles are engaged.
Official judgment:
https://www.supremecourt.uk/cases/uksc-2016-0196.html
Example: R (Bancoult) v Secretary of State for Foreign and Commonwealth Affairs (No 2) [2008] UKHL 61
What happened?
The Chagos Islanders challenged Orders in Council preventing their return to the British Indian Ocean Territory.
The legal issue:
Were the Orders an unlawful use of prerogative power?
The House of Lords’ decision:
By a majority, the court upheld the legality of the Orders. The power exercised fell within lawful authority.
Why this matters:
Judicial review UK does not automatically invalidate executive decisions. Courts will uphold actions taken within legal limits.
BAILII judgment:
https://www.bailii.org/uk/cases/UKHL/2008/61.html
Procedural Unfairness
Public authorities must act fairly and comply with natural justice.
Example: Ridge v Baldwin [1964] AC 40
What happened?
A Chief Constable was dismissed without being given a proper opportunity to respond to allegations.
The legal issue:
Was the dismissal unlawful because no fair hearing had been provided?
The House of Lords’ decision:
Yes. The decision was quashed because fairness required the claimant to be heard.
Why this matters:
This remains a foundational case in judicial review UK. Even powerful decision-makers must follow fair procedures.
BAILII judgment:
https://www.bailii.org/uk/cases/UKHL/1963/2.html
Example: R (Begum) v Headteacher and Governors of Denbigh High School [2006] UKHL 15
What happened?
A student challenged her school’s refusal to allow her to wear a particular form of religious dress.
The legal issue:
Was the decision procedurally unfair or disproportionate?
The House of Lords’ decision:
The claim failed. The school had considered the issue carefully, followed policy, and acted within its discretion.
Why this matters:
Judicial review UK requires fairness — not perfection. Courts will not intervene simply because a claimant disagrees with the outcome.
BAILII judgment:
https://www.bailii.org/uk/cases/UKHL/2006/15.html
Irrationality
A decision may be unlawful if it is so unreasonable that no reasonable authority could have made it. This is a high threshold.
Example: R v North and East Devon Health Authority, ex parte Coughlan [2001] QB 213
What happened?
A severely disabled claimant had been promised a “home for life” in a care facility. The authority later decided to close it.
The legal issue:
Was it lawful to reverse that promise?
The Court of Appeal’s decision:
No. The authority’s reversal was irrational and breached the claimant’s legitimate expectation.
Why this matters:
The case illustrates how judicial review UK protects individuals who have relied on clear and specific assurances from public bodies.
BAILII judgment:
https://www.bailii.org/ew/cases/EWCA/Civ/1999/1871.html
Example: R (Association of British Civilian Internees) v Secretary of State for Defence [2003] EWCA Civ 473
What happened?
Claimants challenged the structure of a compensation scheme introduced by the Government.
The legal issue:
Was the scheme irrational because it excluded certain categories?
The Court of Appeal’s decision:
The challenge failed. Policy decisions involving public expenditure were not irrational merely because they were controversial.
Why this matters:
Judicial review UK does not allow courts to substitute their own policy judgments for those of elected authorities.
BAILII judgment:
https://www.bailii.org/ew/cases/EWCA/Civ/2003/473.html
Proportionality (Human Rights)
Where rights under the Human Rights Act 1998 are engaged, courts assess whether interference is proportionate.
Example: R (Daly) v Secretary of State for the Home Department [2001] UKHL 26
What happened?
Prison officers searched cells and examined legally privileged correspondence outside prisoners’ presence.
The legal issue:
Was this interference with Article 8 rights proportionate?
The House of Lords’ decision:
No. The policy went further than necessary and was disproportionate.
Why this matters:
Judicial review UK requires structured balancing where fundamental rights are involved.
BAILII judgment:
https://www.bailii.org/uk/cases/UKHL/2001/26.html
Example: R (SC) v Secretary of State for Work and Pensions [2021] UKSC 26
What happened?
The two-child benefit cap was challenged as discriminatory and disproportionate.
The legal issue:
Did the policy breach Convention rights?
The Supreme Court’s decision:
The claim failed. The policy pursued legitimate aims and fell within Parliament’s margin of discretion.
Why this matters:
Courts respect parliamentary choices in socio-economic matters unless clearly unlawful.
Official judgment:
https://www.supremecourt.uk/cases/uksc-2019-0139.html
Judicial Review UK in immigration cases
Judicial review UK plays a particularly significant role in immigration law, especially where no statutory right of appeal exists.
Example: R (Medical Justice) v Secretary of State for the Home Department [2010] EWHC 1925 (Admin)
The High Court held that a Home Office policy allowing removal without notice in certain cases was unlawful. The policy failed to provide adequate procedural safeguards.
BAILII judgment:
https://www.bailii.org/ew/cases/EWHC/Admin/2010/1925.html
Immigration judicial review often involves urgent applications, interim relief, and strict procedural compliance.
Costs and risk in Judicial Review UK
Judicial review proceedings carry significant financial exposure.
Key principles include:
- Costs generally follow the event
- Refusal of permission can result in adverse costs
- Protective Costs Orders are limited
- Funding arrangements should be assessed before issuing
Strategic case assessment is essential before proceedings are commenced.
Remedies available
If a judicial review claim succeeds, the court may grant:
- Quashing orders
- Mandatory orders
- Prohibiting orders
- Declarations
- Interim relief
The court does not replace the decision itself but requires the authority to reconsider it lawfully.
Why Judicial Review UK remains constitutionally significant?
Judicial review UK remains one of the central safeguards of the rule of law. It ensures:
- Public authorities act within legal limits
- Fair procedures are followed
- Fundamental rights are respected
- Executive power remains accountable
At the same time, the courts exercise restraint. Judicial review is not a substitute for political disagreement or an appeal on the merits. It is a structured and carefully controlled legal remedy. Understanding both successful and unsuccessful cases illustrates a critical point: judicial review is powerful, but it is not automatic. It depends on clear unlawfulness, timely action, and disciplined legal argument.
