This paper presents problems related to the re-use of public sector information in Poland from the perspective of the Regulation (EU) 2022/868 of the European Parliament and of the Council on European data governance (Data Governance Act). Furthermore, it attempts to answer the question of how much the Polish legal regime's problems related to the application of the Data Governance Act (DGA) are due to the incorrect implementation of the Open Data Directive into national law. The article concludes that the mistake made in the 2011 implementation of Directive 2003/98/EC of the European Parliament and of the Council on the re-use of public sector information of 17 November 2003 has had an impact on the current shape of the re-use of protected data referred to in the DGA. The thesis has been confirmed, the Polish implementation of the Directive contradicts the objectives of that Directive and the DGA. The implementation has also failed to achieve the result intended by the European legislature. This applies to both the objectives of the Directive and the objectives of the DGA. The legislature wanted to create complementary legislation on data re-use. The regulatory environment in which the DGA will operate does not provide a high level of legal certainty, which has implications for the harmonization of European Union law. As the article demonstrates, in Poland there are competing regulations for re-use. This will hinder the achievement of the objectives set for the DGA and the implementation of this Regulation by national obliged entities. It may also affect the actions of those applying for data access. As a consequence of that mistake, there is lack of clear and readable procedures in national law. This should be considered a barrier to the re-use of protected data.