The EAT holds in Esso Petroleum Co Ltd v (1) Jarvis and others (2) Brentvine Ltd that an employment tribunal which expressly found that there was no contract, either written or oral, between a client company and a worker supplied to it by an employment agency, erred in law in going on to rule that the existence of factors consistent with a contract of employment subsisting, and the fact that the worker had worked continuously for the client company for nine years, made her an employee of the client company.