Vicarious liability operates by making an employer liable for wrongs committed by an employee, even when there is no fault on the part of the employer.  A two-stage test must be satisfied:

  • the relationship between the wrongdoer and the organisation alleged to be liable is capable of giving rise to vicarious liability; and
  • there is a sufficient connection between the employment (or other relationship) and the alleged wrongful act.

Both stages of the test have been considered by the Supreme Court in joined cases.

Mohamud v W M Morrison Supermarkets plc arose out of a brutal and unprovoked assault by a supermarket employee on a customer who came into one of the supermarket's petrol stations and asked if he could print a document. The Supreme Court has overturned the Court of Appeal and decided that the connection between the assault and the employee's duties was strong enough to make the employer vicariously liable.

The nature of the employee's job had to be looked at broadly. Here, the employee's job was to attend to customers and, although his conduct was clearly inexcusable, it was within his "field of activities". What happened after, when he left the kiosk and followed the customer onto the forecourt, was an unbroken sequence of events, with the employee trying, violently, to get the customer off his employer’s premises. Although it was a gross abuse of his position, it was in connection with his job serving customers. The fact that he was motivated by personal racism rather than a desire to help his employer's business was immaterial.

The other claim, Cox v Ministry of Justice, was made by a prison catering manager. One of her jobs was to supervise prisoners who worked in the kitchen alongside catering staff. While carrying out her instructions to take supplies to the kitchen stores, one of the prisoners accidentally dropped a sack of rice onto the claimant's back, injuring her.

The Court of Appeal and now the Supreme Court have decided that the prison service was vicariously liable because, even though it was not the prisoner's employer, its relationship with the prisoner was analogous to that between employer and employee. The prisoner worked as an integral part of the prison service's catering business and the risk of the accident was created by assigning those activities to him.