Ashmore, Benson, Pease & Co Ltd v A V Dawson Ltd [1973] 1 WLR 828
Performing a lawful contract in an illegal way renders the contract void.
Facts
In 1967 the plaintiffs, Ashmore, Benson, Pease & Co, manufactured tube tanks. The defendants, AV Dawson, a haulage company, agreed to carry the plaintiff’s equipment by lorry. With the knowledge of the plaintiff’s transport manager, the defendants loaded their vehicle in excess of the weight permitted by the Road Traffic Act 1960, s.64(2). The vehicle toppled over during the journey, and the plaintiffs sued in negligence for £2,225 in damage caused to the equipment by the defendant’s driving. At first instance the trial judge found in favour of the plaintiffs and awarded damages. The defendants appealed.
Issues
The defendant hauliers claimed that the contract was void for illegality. They argued that the equipment had been loaded by the plaintiff’s own servants and the load had exceeded the law with the plaintiff’s knowledge and assistance. They also claimed that the plaintiff’s transport manager had insisted the tubes be carried by lorry even though they knew this would exceed the legal weight limit. Therefore, the parties had a common design in an unlawful purpose.
Decision/Outcome
The Court of Appeal reversed the trial judge’s decision. It held that the contract was void for illegality. Although the contract itself was not illegal, it had been performed in a manner that was illegal with the knowledge and agreement of the plaintiff. If a party enters into a lawful contract and it is agreed that contract is to be carried out unlawfully, that party cannot recover damages for its breach.
Updated 19 March 2026
This case summary remains accurate. Ashmore, Benson, Pease & Co Ltd v A V Dawson Ltd [1973] 1 WLR 828 is a well-established Court of Appeal authority on illegality in contract, and the facts and outcome described are correctly stated.
Readers should be aware of one important legal development. The Supreme Court’s decision in Patel v Mirza [2016] UKSC 42 significantly reformed the law of illegality in England and Wales, replacing the earlier rule-based approach with a flexible, policy-based test. Under Patel v Mirza, courts now consider whether enforcing a claim would be harmful to the integrity of the legal system, taking into account the underlying purpose of the rule breached, any relevant public policy considerations, and proportionality. The Ashmore case itself has not been overruled and remains good authority for the principle that participation in illegal performance can bar a claimant’s recovery, but its reasoning must now be understood in the context of the Patel v Mirza framework. Students should not apply the older rigid approach in isolation without reference to this development.
The Road Traffic Act 1960 has long since been repealed and replaced by subsequent legislation, including the Road Traffic Act 1988, though this does not affect the legal principles established by the case.
