The legal Maxim “Ex-officio” denotes by virtue of office.
Certain powers are only vested to the person in authority of that power or office. These powers are automatically transferred to the person by virtue of the office. For example, The vice president to be ex-officio Chairman of the council of states. Article 64 of the constitution of India provides that the Vice-President shall be ex-officio Chairman of the Council of states and should not hold any office of profit.