Section 33A. The annual budget shall include sums sufficient to pay the salaries of officers and employees fixed by law or by ordinance. Notwithstanding any contrary provision of any city charter, no ordinance providing for an increase in the salaries or wages of municipal officers or employees shall be enacted except by a two thirds vote of the city council, nor unless it is to be operative for more than three months during the calendar year in which it is passed. No new position shall be created or increase in rate made by ordinance, vote or appointment during the financial year subsequent to the submission of the annual budget unless provision therefor has been made by means of a supplemental appropriation. No ordinance, vote or appointment creating a new position in any year in which a municipal election is held shall be valid and effective unless said ordinance, vote or appointment is operative for more than three months during said municipal election year.