Ultra vires

The position is now regulated by the Companies Act 2006, sections 31 and 39, which similarly significantly reduces the applicability of ultra vires in corporate law.

Almost unheard of in modern times, ultra vires acts by the Crown or its servants were previously a major threat to the rule of law.

In the seminal case of Anisminic v Foreign Compensation Commission,[12] Lord Reid is credited with formulating the doctrine of ultra vires.

However, ultra vires, together with unreasonableness, was mentioned much earlier by Lord Russell in the well-known case, Kruse v Johnson,[13] regarding challenging by-laws and other rules.

Anisminic is better known for not depriving courts of their jurisdiction to declare a decision a nullity, even if a statute expressly prevents it from being subject to judicial review.

In Hammersmith and Fulham London Borough Council v Hazell,[16] the House of Lords held that interest rate swaps entered into by local authorities (a popular method of circumventing statutory restrictions on local authorities borrowing money at that time) were all ultra vires and void, sparking a raft of satellite litigation.

Mark Elliott (St Catharine's College, Cambridge) proposes a modified ultra vires doctrine for administrative law, placing it firmly in the correct constitutional setting.