## Introduction

Judicial review allows the courts to examine whether public authorities have acted lawfully. Two well-known standards shape how courts assess the reasonableness of those decisions: Wednesbury unreasonableness and proportionality.

Wednesbury unreasonableness comes from Associated Provincial Picture Houses Ltd v Wednesbury Corporation [1948] 1 KB 223 and sets a very high bar: a decision must be so unreasonable that no sensible authority could ever have reached it. Proportionality, drawn from European legal traditions and now central where Convention rights are engaged under the Human Rights Act 1998 (HRA), asks whether a measure pursues a proper aim, is suitably connected to that aim, is no more than necessary, and strikes a fair balance. This guide explains each test, when they are used, and how to apply them with leading cases.

## What You'll Learn

- What Wednesbury unreasonableness means and how “irrationality” fits within it
- The proportionality test (legitimate aim, rational connection, necessity, fair balance)
- When courts use each standard, and where they may converge
- Key cases: Wednesbury, GCHQ, Daly, Bank Mellat (No 2), Kennedy, and Pham
- How to frame grounds, develop evidence, and argue alternatives in practice
- Common pitfalls to avoid when relying on either standard

## Core Concepts

### Wednesbury Unreasonableness

- Definition and source
  - From Wednesbury [1948] 1 KB 223: a decision is unlawful if it is “so unreasonable that no reasonable authority could ever have come to it.”
  - Reaffirmed as “irrationality” in Council of Civil Service Unions v Minister for the Civil Service [1985] AC 374 (GCHQ).

- What it asks
  - Is the decision so extreme in its logic or moral acceptability that it falls outside the range of responses open to a public body?
  - Courts do not re-make the decision; they check whether the decision falls beyond the outer limits of reasonableness.

- Intensity
  - The threshold is deliberately high. In areas of policy, resource allocation, and technical judgment, courts tend to be cautious.
  - Where important interests are at stake (for example, liberty or asylum), courts may apply “anxious scrutiny” but still in a Wednesbury frame unless proportionality is the correct test.

- Strengths and limits
  - Strengths: respects roles of elected and expert decision-makers; simple headline rule.
  - Limits: relatively unstructured; reasons for intervention may be hard to predict; claimants face a steep uphill task.

- Quick example
  - A local authority imposes a blanket ban on music in parks after a handful of complaints. Under Wednesbury, the question is not whether the court would have chosen a different policy, but whether the ban is so extreme that no reasonable authority could impose it.

### Proportionality

- Definition and source
  - In rights cases under the HRA, courts apply proportionality. Key authorities include R v Secretary of State for the Home Department, ex parte Daly [2001] UKHL 26 and Bank Mellat v HM Treasury (No 2) [2013] UKSC 39.

- The standard four-stage test
  1. Legitimate aim: Is the objective proper and sufficiently important?
  2. Rational connection: Is the measure logically connected to that aim?
  3. Necessity: Is there a less restrictive means that would achieve the aim?
  4. Fair balance: Do the advantages outweigh the severity of the measure’s impact on the individual?

- What it asks
  - Proportionality is structured and transparent. It invites evidence on aims, alternatives, and impacts, and it requires public bodies to justify why a chosen measure is necessary and suitably balanced.

- How it differs from Wednesbury
  - Proportionality involves explicit weighing and comparison; Wednesbury focuses on whether a decision falls outside any reasonable range.
  - Under proportionality, courts may examine the factual record and the choice between options more closely.

- Quick example
  - The same park ban analysed above: the court asks whether noise reduction is a proper aim, whether a total ban is connected to that aim, whether limiting hours would suffice, and whether the quiet gained outweighs the effect on public assembly.

### When to Use Which Standard

- Rights engaged (HRA 1998)
  - Where a Convention right is in play and the interference must be justified, proportionality is the correct test (e.g., Daly; Bank Mellat (No 2)).
- Outside rights cases
  - Wednesbury remains the general common-law standard. The Supreme Court has not replaced it across the board.
- Convergence and debate
  - In Kennedy v The Charity Commission [2014] UKSC 20, the Court signalled that common-law review can sometimes be more structured than classic Wednesbury.
  - In Pham v Secretary of State for the Home Department [2015] UKSC 19, several Justices observed that intensified reasonableness review can look very close to proportionality.
  - In Keyu v Secretary of State for Foreign and Commonwealth Affairs [2015] UKSC 69, the Court declined to adopt proportionality wholesale at common law. The question remains open for a future case.

## Key Examples or Case Studies

### Associated Provincial Picture Houses Ltd v Wednesbury Corporation [1948] 1 KB 223

- Facts: A cinema licence for Sunday opening was granted on condition that no children under 15 were admitted. The operator challenged the condition.
- Holding: The court refused to interfere. Lord Greene MR set out the now-famous test: a decision must be so unreasonable that no reasonable authority could have reached it.
- Takeaway: Wednesbury sets a very high threshold and does not allow the court to substitute its view.

### Council of Civil Service Unions v Minister for the Civil Service (GCHQ) [1985] AC 374

- Facts: The government banned GCHQ staff from trade union membership on national security grounds without consultation.
- Holding: Judicial review applied to prerogative powers, but the ban was justified due to national security. Lord Diplock identified “irrationality” as a ground of review equivalent to Wednesbury unreasonableness.
- Takeaway: Confirms irrationality as Wednesbury in modern terms; shows limits of intervention in security-sensitive policy.

### R v Secretary of State for the Home Department, ex parte Daly [2001] UKHL 26

- Facts: A policy required prisoners to be absent from their cells during searches of legally privileged material.
- Holding: The policy was disproportionate and unlawful. The House of Lords explained why proportionality is a distinct and more exacting tool than Wednesbury in rights cases.
- Takeaway: Proportionality tests necessity and fair balance; it can lead to a closer look at justification and alternatives.

### Bank Mellat v HM Treasury (No 2) [2013] UKSC 39

- Facts: A direction effectively excluded an Iranian bank from the UK financial sector due to alleged links to Iran’s nuclear programme.
- Holding: The direction was quashed as disproportionate. The Supreme Court set out a four-limb analysis focusing on aim, connection, necessity, and fair balance.
- Takeaway: A clear model of proportionality in action, with careful scrutiny of evidence and alternatives.

### Kennedy v The Charity Commission [2014] UKSC 20 and Pham v Secretary of State for the Home Department [2015] UKSC 19

- Kennedy: The Court preferred to resolve the case by reference to common-law principles rather than Article 10 ECHR, indicating that a more structured form of review may be used where appropriate.
- Pham: Several Justices observed that an intensified reasonableness review can merge with proportionality in practice, though the Court stopped short of a general shift at common law.
- Takeaway: There is movement towards transparency and structure even outside HRA claims, but Wednesbury has not been displaced in general.

## Practical Applications

- Choosing and framing your ground
  - Rights engaged: Plead proportionality under the HRA. Identify the specific right and show an interference that requires justification.
  - No rights engaged: Plead Wednesbury unreasonableness. Where appropriate, also argue for intensified scrutiny and present proportionality-style reasoning as an alternative if the court accepts it.
  - Mixed cases: It can be sensible to plead both, explaining why proportionality applies (rights) or, failing that, why the decision still falls outside any reasonable range.

- Building the evidential record
  - Aim: Obtain documents identifying the decision’s objective (e.g., policy papers, minutes).
  - Connection: Seek material showing how the measure is expected to achieve the aim (impact assessments, modelling).
  - Alternatives: Press for disclosure of options considered and why less restrictive measures were rejected.
  - Effects: Gather evidence of the measure’s impact on individuals or groups (statements, data, expert reports).

- Presenting the argument
  - Under Wednesbury: Focus on features showing the decision sits outside the range of reasonable outcomes (e.g., glaring inconsistency with evidence, ignoring mandatory considerations, manifest disproportionality).
  - Under proportionality: Walk through each stage. If one limb fails (often necessity), the decision should fall.
  - Offer workable alternatives. Courts take proposals seriously where they meet the aim with less harm.

- For public authorities
  - Record the aim and the legal power relied on.
  - Document the options considered and why the chosen measure was preferred.
  - Assess and record impacts on rights and interests.
  - Keep reasons clear and specific. This aids both Wednesbury defensibility and proportionality justification.

- Common pitfalls
  - Treating Wednesbury as an appeal on the merits. It is not.
  - Arguing proportionality without identifying a Convention right or statutory context that calls for it.
  - Failing to propose realistic alternatives when arguing necessity.
  - Ignoring the need for evidence to support each limb of proportionality.

## Summary Checklist

- Know the Wednesbury test: “so unreasonable that no reasonable authority could have come to it”
- In rights cases, apply proportionality: aim, connection, necessity, fair balance
- Use Daly and Bank Mellat to structure proportionality arguments
- Outside rights cases, Wednesbury is generally the standard, though intensity varies
- Kennedy and Pham show a trend towards structured reasoning at common law
- Build evidence on aims, options, and impacts; propose less restrictive alternatives
- For public bodies, record reasons and options to withstand either standard

## Quick Reference

| Concept                      | Authority                                              | Key Takeaway                                                                        |
| ---------------------------- | ------------------------------------------------------ | ----------------------------------------------------------------------------------- |
| Wednesbury unreasonableness  | Wednesbury [1948] 1 KB 223; GCHQ [1985] AC 374         | Very high threshold; outside the range of reasonable outcomes                       |
| Proportionality (HRA)        | Daly [2001] UKHL 26; Bank Mellat (No 2) [2013] UKSC 39 | Four-stage test: aim, connection, necessity, fair balance                           |
| Rights trigger               | HRA 1998 s.6                                           | Public bodies must justify interferences with Convention rights                     |
| Structured common-law review | Kennedy [2014] UKSC 20                                 | Courts may use more structured analysis even outside HRA                            |
| Convergence debate           | Pham [2015] UKSC 19; Keyu [2015] UKSC 69               | Intensified reasonableness can resemble proportionality; no general replacement yet |

Wednesbury vs Proportionality in Judicial Review