The city, nor any officer, agent or employee thereof, nor any person acting or purporting to act on behalf of the city, nor an officer, agent or employee thereof, shall, with respect to any public construction contract, require or attempt to require a contractor or any subcontractor to make application to or to procure or obtain from any particular insurance or surety company, agent or broker, any of the bonds or insurance required by this chapter. (1985 Code § 7-330)