Section 92A. No employee of any department, board or commission of the city shall, directly or indirectly, give, solicit or receive, or in any manner be concerned in giving, soliciting or receiving any assessment, subscription or contribution for any political party or for any candidate for city office. Whoever violates any provision of this section shall be punished by a fine of not more than five hundred dollars or by imprisonment for not more than six months, or both, and upon final conviction thereof his office or position in the service of the city shall thereby be vacated and he shall never again be eligible for any office or position, elective or otherwise, in the service of the city.