The article analyses the problem of the scope of relative nullity (invalidity) of public procurement contracts in the light of the provisions of the Public Procurement Law. This analysis is conducted in the context of one of the conditions for mandatory invalidation of a contract award procedure, which is an irremovable defect of the proceedings that prevents the conclusion of a contract that is not subject to cancellation. The scope of this ground for invalidating the procedure is strictly dependent on the statutory scope of invalidity of public procurement contracts. The study presents far-reaching discrepancies in interpretation, in particular in case law, resulting from the removal in the applicable regulation of the grounds for invalidating a public procurement contract of the grounds for violating the provisions of the Act in the proceedings, which had or could have had an impact on the outcome of the proceedings. The article presents, inter alia, a proposal for such an interpretation of the relevant provisions of the current Public Procurement Law that avoids the consequences of having to conclude procurement contracts affected by significant procedural defects, including such violations of the provisions of the Law that distort the outcome of the procedure – the selection of the most advantageous offer.