No member of the city commission, the city manager or any other officer or employee of the city, shall directly or indirectly be interested in any contract, job, work or service with or for the city; nor in the profits or emoluments thereof, nor in the expenditure of any money on the part of the city other than his fixed compensation; and any contract with the city in which any such officer or employee is, or becomes, interested may be declared void by the city commission.
No member of the city commission, the city manager or other officer or employee of the city shall knowingly accept any gift, frank, free ticket, pass, reduced price or reduced rate of service from any person, firm or corporation operating a public utility or engaged in business of a public nature within the city, or from any person known to him to have or to be endeavoring to secure a contract with the city. But the provisions of this section shall not apply to the transportation of policemen or firemen in uniform or wearing their official badges, when the same is, or may be, provided by ordinance.