Supreme Court takes chance to clarify law on loss of chance

18 March 2019

In Perry v Raleys Solicitors[1] the Supreme Court has provided important guidance on how “loss of chance” professional negligence cases should be approached.


Mr Perry was a retired miner, afflicted from medical conditions brought about by excessive exposure to the effects of using vibratory tools.  In 1999, a scheme was set up to provide tariff based compensation to miners who had been exposed to excessive vibration and had suffered medical conditions as a result. The scheme created two bodies of compensatory awards which broadly corresponded with general and special damages for personal injuries (the latter which could include an additional “Services Award”).

Mr Perry instructed Raleys Solicitors (“Raleys”) to pursue a claim under the scheme. That claim was successfully settled in November 1999 for general damages only. No claim was made in respect of the “Services Award”. Mr Perry sued Raleys alleging that their negligent failure to provide appropriate advice meant that the he had lost the opportunity to claim the Services Award, quantified in the sum of £17,300.17.

First Instance Decision

In the first instance, the Court rejected that the breach had caused the Respondents loss. The Court deemed that the Respondent would not have been able to make an honest claim for a Services Award and causation was therefore not established.

Court of Appeal Decision

The Court of Appeal reversed the first-instance decision on errors of fact and law, holding that: (1) the trial judge had mistakenly conducted a “trial within a trial” as to the likelihood of success of Mr Perry attaining a Services Award, and (2) imposing a burden upon Mr Perry to prove on the balance of probabilities that he satisfied the requirements for the Services Award.

Supreme Court Decision

The Supreme Court upheld the first-instance decision reversing the Court of Appeal decision. The Court clarified the law in respect of loss of chance and causation, conceding that the what-if scenarios regarding causation are counter-factual and have given rise to conceptual and practical difficulties.

The Court affirmed that the correct approach was that in Allied Maples Group Ltd v Simmons & Simmons[2] to the effect that if a party receives negligent advice in relation to pursuing a benefit (the lost chance) the following principles apply:

  1. When assessing what the claimant would have done upon the receipt of competent advice, this must be proved by the claimant upon the balance of probabilities. The claimant must prove that they would have acted in a specific way and would have gained a benefit for so doing.
  2. When assessing what a third party would have done, for instance whether a solicitor would have advised in a certain way which would have benefitted the claimant, this depends on a loss of chance evaluation, in respect of which it may be appropriate to conduct a “trial within a trial”.

The decision is not new law, but helpfully reaffirms the position set down over 20 years ago in Allied Maples and clarifies that those principles remain in place. However, one interesting, albeit obvious gloss that the Supreme Court has placed on those principles is that a claimant asserting that they would have pursued a particular course of action must have a honest belief that they would have done so.

Co-authored by Thomas Wilkinson, Administrator

[1] [2019] UKSC 314

[2] [1995] 1 WLR 1602


Leigh Callaway Author
Leigh Callaway
Senior Associate
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