Law Case Summary
Mohamud v WM Morrison Supermarkets plc [2016] UKSC 11
Tort law – Vicarious liability – Assault
Facts
Mohamud had used a petrol station kiosk and approached a member of staff with a question. The employee responded in an aggressive manner and demanded that Mohamud leave immediately. As he left the employee assaulted him. Mohamud bought an action against the supermarket, claiming that it was vicariously liable for the assault committed by one of its employees. The trial judge rejected the claim on the basis that there was not a sufficient link between the employee’s role and the assault. A subsequent appeal of the decision was rejected the Court of Appeal. Mahmoud subsequently appealed to the Supreme Court.
Issues
The basis of Mohamud’s appeal was that there should be a new test with regards to vicarious liability which weighed whether a reasonable observer would consider the employee to acting as a representative of an employer. This was an important consideration as the test had been employed for a significant amount of time prior to this challenge.
Decision/Outcome
The appeal was allowed. The court held that the current ‘close connection’ test had been used in a number of cases at House of Lords/Supreme Court level and as a result of this; they did not wish to deviate dramatically from precedent. However, the court felt that a simplification of the test was more desirable. This required the consideration of the employee’s functions and whether there was a sufficient connection between the wrongful conduct and the employer. On this basis the court held that whilst it was a gross abuse of his position, it was in connection with the business by which he was employed.
Updated 20 March 2026
This case summary accurately reflects the decision in Mohamud v WM Morrison Supermarkets plc [2016] UKSC 11. The Supreme Court did uphold the ‘close connection’ test and found Morrison’s vicariously liable for the employee’s assault.
However, readers should be aware of an important subsequent development. The Supreme Court revisited and significantly refined the law on vicarious liability in Various Claimants v Barclays Bank plc [2020] UKSC 13 and Various Claimants v Wm Morrison Supermarkets plc [2020] UKSC 12, decided together. In the Morrison appeal, the Supreme Court reversed the Court of Appeal’s finding of vicarious liability on the facts of a data leak case, and in doing so clarified and, to some extent, narrowed the close connection test as it had been applied post-Mohamud. The Supreme Court emphasised that the test requires a genuine connection between the nature of the employment and the wrongful act, and cautioned against an over-broad application of Mohamud. The core principles described in this summary remain good law, but students should read the 2020 Supreme Court decisions alongside this case to understand the current state of the close connection test.
