In case of a vacancy in the office of the City Manager, or in case of the City Manager's absence from the City, temporary disability to act as City Manager, discharge by the Council, or resignation, the Mayor shall act as Manager during such absence or incapacity, unless the Council shall appoint a Manager pro tempore who shall possess the powers and duties of the Manager. No Manager pro tempore, however, may appoint or remove a City officer or employee except with the approval of a majority of the members of the City Council. No Manager pro tempore shall hold his position as such for more than four months, and no appointment of a Manager pro tempore shall be renewed.