Section 111. In any city or town which has accepted chapter two hundred and seventeen of the acts of nineteen hundred and fourteen or has accepted this section in any form, or which accepts this section in the manner hereinafter provided, or has accepted earlier provisions of this section, every permanent civil service employee as well as every person classified as a common laborer, skilled laborer, mechanic or craftsman, shall be granted a vacation of not less than two weeks without loss of pay in each calendar year if he has actually worked for such city or town for thirty weeks in the aggregate during the twelve months preceding the first day of June in such year. Such vacation shall be granted by the head of the respective department of the city or town at such time as in his opinion will cause the least interference with the performance of the regular work of the city or town. Any official of a city or town whose duty it is to grant a vacation as provided by this section who wilfully refuses to grant the same shall be punished by a fine of not more than one hundred dollars. The attorney general shall enforce this section and shall have all necessary powers therefor.

If a petition requesting that the question of acceptance of this section be submitted to the registered voters of any city or town not already subject to this section, signed by registered voters thereof equal in number to at least one per cent of the whole number of registered voters thereof, is filed with the city or town clerk not less than sixty days before a biennial state election, said city or town clerk shall immediately transmit said petition to the state secretary, who shall cause to be placed upon the official ballot to be used in said city or town at said state election the following question: ''Shall section one hundred and eleven of chapter forty-one of the General Laws, providing for vacations for certain municipal employees, be accepted?'' If a majority of the registered voters of such city or town voting thereon vote in the affirmative in answer to said question, said section shall be applicable in such city or town from and after the beginning of the next municipal year.