Rose v Plenty [1976]

An employee who contrary to an express prohibition imposed by his employer engages another to assist him in the performance of his duties may despite the prohibition render his employer vicariously liable for injuries caused to that other by the employee's negligence. The defendant milk roundsman was expressly prohibited by his employers from engaging young persons to assist in the performance of his duties.

None-theless the defendant engaged the 13-year-old plaintiff to assist in the collection…