Suppliers may be prequalified as responsible prospective contractors for particular types of supplies, services, and construction. No supplier shall be prequalified as a responsible prospective contractor until the supplier provides the local public agency with a sworn statement made under penalty of perjury that he has not knowingly violated any provision of the campaign finance laws of the Commonwealth and that the award of a contract to the supplier will not violate any provision of the campaign finance laws of the Commonwealth. "Knowingly" means, with respect to conduct or to a circumstance described by a statute defining an offense, that a person is aware or should have been aware that his conduct is of that nature or that the circumstance exists. Solicitation mailing lists of potential contractors of such supplies, services, and construction shall include, but shall not be limited to, such prequalified prospective contractors. Prequalification shall not foreclose a written determination:
(1) Between the time of bid opening or receipt of offers in the making of an award that a prequalified prospective contractor is not responsible; or (2) That a prospective contractor who is not prequalified at the time of bid opening or receipt of offers is responsible.