One of two irreducible minimum requirements before a contract of employment exists (Court of Appeal in Montgomery v. Johnson Underwood Ltd (2001) – an agency worker case) The Courts ruled that there must be an obligation on the employer to provide work and on the employee to accept it. One of the leading cases concerned waiters who worked at various catering functions. They did not work continually but would be telephoned and offered a particular job. The Court found that the employer did not have to offer them the work nor did they have to accept it. This meant they were not employees due to lack of mutuality of obligation. The second irreducible requirement is covered by the control test. See EMPLOYEE/EMPLOYER RELATIONSHIP.