The Manager may designate, by a letter filed with the Clerk of Council, a qualified administrative officer of the Municipality to perform the powers, duties and functions of the Manager during the temporary absence or disability of the Manager. If the Manager fails to make such designation, the Council may, by the adoption of a motion by a majority vote of its members, appoint a qualified administrative officer of the Municipality to perform such powers, duties and functions during the temporary absence or disability of the Manager. In event of an emergency and the Manager has not filed a letter of designation, the Mayor shall make a temporary appointment of a qualified member of the staff to act as Manager, until the Council acts as required in this section.