Article 9 of Municipality Law

Applications for candidacy for the positions of Council President and his Deputy shall be submitted to the oldest member presiding. The President and Deputy President shall be elected by secret ballot by an absolute majority of the members present. If that majority is not attained, the election shall be repeated between the two obtaining the most votes. If both receive an equal number of votes, lots shall be drawn between them to determine the winner. If either seat becomes vacant, the Council shall announce this at its first sitting after the vacancy occurs, and the Council shall elect a replacement until the end of his term. The election shall be held at the first sitting following the announcement of the decision declaring the vacancy of the President's or his Deputy's seat. Members may select one of their number as President or Deputy President by acclamation.