Lecture 21: Unreasonableness

Question 1

What is Wednesbury unreasonableness?

Answer 1

Wednesbury unreasonableness refers to a decision so unreasonable that no reasonable authority could have made it—established in Wednesbury Corp [1948].

Question 2

How has the concept of unreasonableness evolved?

Answer 2

Once called Wednesbury unreasonableness, it’s now known as irrationality or simply unreasonableness, making judicial review more flexible.

Question 3

What are the two types of rationality review?

Answer 3

Rationality review looks at:

Process rationality – was the decision made logically and with relevant facts?
Outcome rationality – is the result so unreasonable no sensible authority would choose it?

Question 4

What is meant by a flexible standard of review?

Answer 4

A flexible standard means courts adjust how strictly they review a case, depending on how serious the issue is (e.g. Begbie [2000], Q [2004]).

Question 5

Why is proportionality considered controversial in judicial review?

Answer 5

Proportionality is controversial because it lets courts assess not just legality but also the merits of decisions—considered more intrusive

Question 6

Is proportionality becoming a common law ground of review?

Answer 6

Yes, potentially—UK courts have hinted that proportionality might develop into a common law ground of review, as seen in Pham v Secretary of State for the Home Department [2015] UKSC 19