Further provisions as to execution of contracts and agreements

(1) Subject to the provisions of sections 24 and 25, the contracts or agreements shall be made or executed in accordance with such rules as may be made. (2) The provisions of sub-section (1) shall apply to every variation or abandonment of a contract or estimate as well as to an original contract or estimate. (3) A contract or agreement made or executed in contravention of the provisions of thisAct or the rules or regulations made thereunder shall not be binding on the Board.