In Kleinwort Benson, Lord Goff opined that the retroactive effect of judicial decisions was inevitable. He added that:
The only alternative, as I see it, is to adopt a system of prospective overruling. But such a system, although it has occasionally been adopted elsewhere with, I understand, somewhat controversial results, has no place in our legal system.
Lord Hope expressed exactly the contrary view when he proposed that prospective overruling take place in Hall v Simons. That case changed the law so that advocates were no longer immune from being sued for negligence. No other member of the House in that case discussed prospective overruling, and so the abolition of advocates’ immunity had the ordinary retroactive effect. It applied to any causes of action arising prior to the announcement of the abolition that were not already res judicata and had not expired by force of the statute of limitations.
Litigants have, however, requested that the temporal effect of judgments in the United Kingdom be controlled in others ways. In Ahmed v HM Treasury, the Supreme Court struck down Executive Orders designed to prevent the financing of acts of terrorism on the basis that they were ultra vires the statute under which they were issued.
Restrictions placed on individuals under the Orders were thus ‘imposed without authority and are of no effect in law’. They were void ab initio. The Treasury asked the Supreme Court to suspend its orders so that restrictions placed by banks on the funds of the individuals concerned would ‘persist until the invalid restrictions can be replacedby restrictions that have the force of law’.
It is clear that the United Kingdom has the power to suspend the effect of its orders if it sees fit to do so. It is equally clear that this is not a form of prospective overruling, but only a delay in the taking effect of a judgment, which, once it has taken effect, will apply to the facts that gave rise to it and to all cases decided from then on regardless of when the facts giving rise to them occurred, subject to any legislative intervention in the meantime. Lord Hope thought that the Supreme Court should suspend the effect of its orders in this case, but the rest of the court disagreed, holding that ‘it would not be appropriate to suspend any part of the court’s order’ because: ‘This could should not lend itself to a procedure that is designed to obfuscate the effect of its judgment’. The Executive Orders were ultra vires and so, the court considered, they should be struck down without delay.
(The Temporal Effect of Judgemnts in the United Kingdom în The Effect of Judicial Decisions in Time, Intersentia, 2014, la pp. 168-70)