A. All statements or invoices submitted to the awarding public agency for work performed shall contain a certification by the supervising architect or engineer, or other supervisory official if no supervisory architect or engineer is employed for the project, that work for which payment is claimed has been performed and that such work conforms to the plans and specifications for the project. No such statement or invoice shall be paid by the awarding public agency without such certification. The execution of a certificate, as herein provided, shall not constitute a defense or in any other manner affect any cause or causes of action which the awarding public agency might otherwise have against the contractor for nonperformance of a public construction contract.

B. If project progressive payments are based on the public agency's estimated quantities of materials provided and work performed, certifications are not required. Payment of progressive estimates shall not constitute a defense or in any manner affect any cause or causes of action which the awarding public agency might have against the contractor for failure to properly perform in accordance with the project contract, plans, specifications, or special provisions. Final estimates shall contain a sworn certification signed by the contractor that the work performed and the material provided conform to the requirements of the contract, plans, specifications, and special provisions.