What Law says

Labour Law UAE No 8 of 1980, article 88, states in details that, Any worker can not or shall not work for another company/employer if he is on annual vacations/leave or he is on sick leave. If the Employer finds out or has found out that employee is working for someone else, then he is entitled to terminate the services without notice.

This Article and Clause of the Law states that no one is allowed to work for another company or employer if he or she is on annual vacations or on sick leave. In such a scenario, Employer has the right to terminate the services. If something needs to be resolved as per the Law, then he can raise the complaint or demand from the employee as well, which depends on the situation. But in short, Law gives an option to Employer to terminate the services. This is the beauty of the Law, provided by the Law. Lawyers can also support Employer if he wants.