The aim of the article is to determine the prerequisites, scope, as well as the legal nature of the contracting authority's liability for payment of due remuneration to subcontractors resulting from the provisions of the Public Procurement Law (Article 465 in connection with Article 464). It is particularly associated with answering the question of whether the contracting authority and the contractor are jointly and severally liable towards subcontractors or in solidum? The further objective is to examine the systemic relationships between the aforementioned provisions of the PPL and the provisions of the Civil Code (Article 6471, Article 366 and subsequent articles of the Civil Code) establishing analogous liability of the investor (including the contracting authority) for payment of due remuneration to subcontractors in construction contracts. This raises the question of whether this relationship is determined by the principle of lex specialis derogat legi generali, or if there is a concurrence of legal regimes? Resolving these issues is of significant importance from a doctrinal point of view, and also affects the interpretation of the aforementioned provisions of the law, and thus the effectiveness of protecting subcontractors' claims.

The commentary concerns an interesting issue whether, based on the principle of freedom of contract (Article 3531 of the Civil Code), the provisions on „quasi-contractual penalties” consisting in the obligation to pay a specified amount to the creditor in the event of withdrawal from the contract due to the debtor's delay in performing of monetary obligation, should be considered valid. This is an important problem for practice, as this kind of „penalties” under various names are often used. The view of the Supreme Court that denies the admissibility (validity) of such provisions deserves approval and the commentary presents a number of further legal arguments strengthening this position.

The commentary concerns a significant judgment of the Supreme Court, which specifies the criteria for assessing the validity of the contractual penalties, the amount of which has been expressed using measures of value other than the specified sum. The views of the Supreme Court both as regards the definition of the aforementioned criteria and the inadmissibility of reserving contractual penalties in a non-pecuniary form in the Polish legal system deserve full approval. The commentary presents additional argumentation resulting from the functional, systemic and comparative interpretation of law supporting the views expressed by the Supreme Court as well as the impact of the commented judgment on contractual practice.