Material Contribution
An alternative test for causation used where the but-for test fails: the defendant's breach need only have materially contributed to the damage (Bonnington Castings v Wardlaw [1956]).
Independent editorial summary — not the official statute text. Read the official version on legislation.gov.uk.
Ordinarily a claimant must prove that, but for the defendant's negligence, their injury would not have happened. The Court of Appeal in Bailey v Ministry of Defence explained that this strict test is relaxed in a narrow category of cases: where medical science cannot establish the probability that 'but for' an act of negligence the injury would not have happened, but can establish that the contribution of the negligent cause was more than negligible, the 'but for' test is modified, and the claimant will succeed.
This 'material contribution' approach traces back to Bonnington Castings Ltd v Wardlaw [1956], where a claimant who had inhaled dust from both a negligent and a non-negligent source did not have to prove which source caused his disease, only that the negligent source made a material contribution — meaning something more than negligible — to it. The Court of Appeal in Bailey applied the same reasoning to a claimant whose weakened physical state, caused by both negligent and non-negligent factors, led to her injury.
Related terms
Official sources
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