The decisions sketch a coherent constitutional doctrine of sustainability in Hungary. First, the State bears an institutional protection obligation: legislating, implementing, and enforcing rules (including measurable standards like limit values) that effectively guard environmental quality. Second, non-regression operates as a structural constraint: once environmental protection reaches a certain level, it cannot be lowered casually; any relaxation demands rigorous justification and proportionate tailoring. Third, precaution and prevention are action-guiding: uncertainty about serious environmental harm triggers a duty to regulate in advance rather than to react ex post. Fourth, intergenerational justice functions as a constitutional metric for policy adequacy—laws must preserve ecological options, quality, and access for those not yet represented. Finally, the Constitutional Court resists efforts to subordinate environmental protection to short-term economic aims, insisting that environmental constitutional rights and duties set binding limits on policy trade-offs.

For the preliminaries, in relation to the previous constitution (Act XX of 1949 The Constitution of the Republic of Hungary), Article 18 stated that the Republic of Hungary recognises and shall implement the individual’s right to a healthy environment. The Constitutional Court, in its Decision 996/G/1990. AB, established that, based on the above constitutional provisions, the State is obliged to establish and operate specific institutions serving the implementation of the right to a healthy environment. It further established that neither the wording of Section 18 (the right to a ‘healthy environment’) nor the inclusion of the State’s environmental protection task among the means of implementing the right to health can be interpreted as a restriction of the right to the environment. The foundational understanding stems from Decision 28/1994 (V. 20.) AB, which also formulated a proto-non-regression rule: once the legal system reaches a given level of environmental protection, the State may not lower it without compelling constitutional justification and strict proportionality.2 The Constitutional Court found that the lack of regulation regarding the transfer of all nature conservation areas and areas planned for protection to the original level of nature conservation, which do not result in the restoration of nature conservation, to state ownership and management by nature conservation bodies, or - where possible - the lack of regulation resulting in the same level of protection, creates an unconstitutional situation. Therefore, the Constitutional Court called on the National Assembly to fulfil its legislative task by 30 November 1994. It also declared that in its current form, the right to the environment is not a fundamental right, nor is it merely a constitutional task or state goal, the means of achieving which the State can freely choose. It is well known that the right to the environment cannot be classified as a classic, protective fundamental right, but rather as a so-called third-generation constitutional right, the nature of which is still disputed and which is still contained in only a few contemporary constitutions. Furthermore, the degree of institutional protection of the right to the environment is not arbitrary. In addition to the above dogmatic characteristics of the right to the environment, the level of protection is also decisively influenced by the subject matter of environmental protection: the finiteness of the natural foundations of life and the irreversibility of a significant part of natural damage, and finally the fact that all these are conditions for the survival of human life. The right to the environment ensures the physical conditions for the enforcement of the right to human life.

The present regulation was already mentioned, as summary the Hungarian constitutional law embeds sustainability most explicitly in Article P) of the Fundamental Law, which treats natural resources and biodiversity as part of the nation’s common heritage to be preserved for future generations, and in Article XXI, which guarantees everyone the right to a healthy environment. Early on, the Constitutional Court clarified that this right is primarily objective and institutional in nature: the State must create and maintain regulatory systems and standards that effectively protect environmental quality.

In the field of explaining the right to the environment – ​​or rather its reinterpretation based on the Fundamental Law – further thinking was initiated by Decision 16/2015. (VI. 5.) AB. Point [92] of it refers to Article P) of the Fundamental Law, which describes what environmental protection actually means as a state and citizen obligation and its trinity: (i) protection, (ii) maintenance, and (iii) preservation for future generations.3 It is of great importance that the Fundamental Law also speaks of the obligation of everyone – including civil society and every citizen. This marks the beginning of the interpretation of the rights of future generations.4 The Act on Managing State Land, which would have transferred management rights for state-owned land to the National Land Management Fund, is unconstitutional. The transfer of competences would have affected regulations reserved to cardinal Acts, meaning that a two-third majority in parliament would have been necessary to approve these parts of the Act. The transfer of property management to the National Land Management Fund would reduce the level of environmental protection, as the Fund prioritises mainly economic aspects of managing the land as opposed to ensuring they remain protected nature reserves.

Decision 3104/2017. (V. 8.) AB was the first to pay more attention to the issue of future generations – and, in connection with this, to the protection of the nation’s common heritage.5 This decision emphasises that [39] “…within the scope of general responsibility, the State is entitled to and obliged to have a kind of primacy, priority, since the coordinated enforcement of this responsibility through institutional protection guarantees, the creation, correction and enforcement of institutional protection are directly and primarily state tasks”. Thus, the mandatory aspects of the enforcement of rights are noticeably highlighted. The reference to institutional protection also appeared in the Constitutional Court’s first substantive environmental decision (above mentioned Decision 28/1994 (V. 20.) AB) and has remained unbroken ever since. Institutions – and thus, environmental safety rules and institutions – must be established that are capable of implementing the above-mentioned special responsibility.

Building on that baseline, the Constitutional Court has repeatedly read Article P) through the lens of intergenerational justice. The case started with a petition for posterior norm control submitted against Section 31 of the Government Decree 262/2010. (XI. 17.) on the detailed rules for utilising land parts belonging to the National Land Fund (sale and utilisation of state-owned lands). In Decision 28/2017 (X. 25.) AB on the sale and management of Natura 2000 lands, it found a legislative omission because sufficiently robust nature-conservation guarantees did not accompany privatisation and subsequent land use.6 The Constitutional Court – acting ex officio – found that the Parliament has caused a violation of the Fundamental Law by omission by failing to establish safeguards to enforce the nature conservation aspects of the sale and utilisation of Natura 2000 land parcels that do not qualify as protected natural areas in accordance with the objectives set out in Article P) (1) of the Fundamental Law; therefore called the Parliament to fulfil its legislative obligation by 30 June 2018. The Constitutional Court articulated three duties of the present generation: (i) to preserve options, (ii) to preserve quality, and (iii) to preserve access for future generations. These duties operationalise sustainability in constitutional terms and establish a demanding benchmark for later legislation. Another important aspect of this decision is that it refers to Pope Francis’ encyclical [36] in its reasoning, thus to the ethical foundations in relation to biodiversity.7 The decision continues on the path it has begun with the process of interpreting the Fundamental Law, extending its scope beyond Article P) to Article 38, not forgetting the National Creed. The AB fortunately further strengthens the connection between the protection of future generations and the right to the environment – ​​in point [26] – and then confirms the legal continuity that is now being implemented at a higher level [27], which applies to the entire environmental value system and approach. Point [28] clearly transfers the right to a healthy environment to the area of ​​preservation for future generations. Point [30] clarifies the State’s prominent role within the broader range of obligations that had already appeared, since the state, in addition to legislation, “must also ensure that specific behaviours adopted in the interest of environmental protection are recognisable, unambiguous and legally enforceable.” The next step now leads to a theoretical outline of the protection of the interests of future generations: “[31] … Article P) confers a hypothetical inheritance on future generations.” This gives rise to the State’s specific obligation to protect [32], within which it must consider “the state of the inheritance of future generations.” This constitutes an objective requirement that also includes the prohibition of retrogression. The AB decision then develops Edith Brown Weiss’s ideas further:8 “[33] Pursuant to Article P) of the Fundamental Law, the present generation is burdened with three main obligations: preserving the possibility of choice, preserving quality and ensuring the possibility of access.” The first requires that we do not reach the point where “…the decisions of the present day would put future generations on a forced path”. The second is self-evident, and the third is about resources, where the limit on use is: “as long as the equitable interests of future generations are respected”. An important message of the decision in this context is the encouragement of long-term thinking: “[34] The legislator can only meet these expectations at the level of principles if, when making its decisions, it considers them in the long term, across government cycles.” This requires that decisions related to the environment be planned, thus extending its scope to ​​environmental safety.

The Constitutional Court therefore expects the State’s activities and legislation to fulfil the requirements of the principle. The principle was first addressed in its merits in Decision 27/2017. (X. 25.) AB: “[49] According to the generally accepted principle of precaution in environmental law, the State must ensure that the deterioration of the state of the environment does not occur as a consequence of a given measure.”9 The Constitutional Court found that the National Assembly, in connection with Article P) (1) of the Fundamental Law, caused an unconstitutionality manifested by omission by failing to ensure the creation of a rule, simultaneously with the amendment of Section 28 of Act LXXXVII of 2010 on the National Land Fund, as established by Section 1 of Act CVII of 2016 on the amendment of Act LXXXVII of 2010 on the National Land Fund, that would ensure the long-term preservation of the assets of the National Land Fund protected by cardinal rules and would exclude the possibility that the application of laws acceptable by a simple majority would lead to a loss of assets to an extent that would endanger the achievement of the objectives of the National Land Fund, the protection and maintenance of natural resources, especially agricultural land, forests and water resources, biodiversity, especially native plant and animal species, and their preservation for future generations. The Constitutional Court called on the National Assembly to fulfil its legislative task by May 31, 2018. As we saw in the Decision 28/2017. (X. 25.) AB, the Constitutional Court went even further, emphasising: “[75] In the interest of environmental protection, and thus both when adopting the cardinal law pursuant to Article P) paragraph (2) of the Fundamental Law and when developing detailed regulations for Natura 2000 areas […], the legislator must also take into account the precautionary principle, according to which the State must demonstrate that, taking into account scientific uncertainty, deterioration of the state of the environment will certainly not occur as a result of a given measure.”

The truly great step forward was Decision 13/2018 (IX. 4.) AB in the environmental jurisprudence giving a concrete bite to precaution and prevention.10 The prohibition of retrogression, and the protection of future generations, turned more strongly than ever towards the precautionary principle. The Constitutional Court rejected legal changes that would have allowed unreported and unpermitted extraction of groundwater from shallow wells. Citing Articles P) and XXI, it reasoned those uncertainties about cumulative impacts on aquifers and ecosystems require ex ante safeguards rather than deregulation. The ruling thus reaffirmed that when environmental harm may be serious or irreversible yet uncertain, regulators must act precautionarily, not wait for definitive scientific proof. The prohibition of retrogression has been a key issue of legal interpretation since the initial AB decisions. The Fundamental Law clearly formulated the issue of protecting future generations, while the precautionary principle was only introduced into the AB’s interpretation practice a year earlier. The position is outlined: “[13] …The Fundamental Law, both in terms of the cited provisions of the National Creed and paragraph (1) of Article P), exceeded the provisions of the previously effective Constitution in content… The responsibility towards future generations arising from the Fundamental Law requires the legislator to evaluate and consider the expected impact of its measures on the basis of scientific knowledge, in accordance with the principles of precaution and prevention.” According to the next stage of the construction: “[14] when adopting legislation, not only the individual and common needs of the present generation must be considered, but also the provision of living conditions for future generations must be taken into account, and when considering the expected impacts of individual decisions, it must proceed in accordance with the principles of precaution and prevention.” In addition to legislation, the practice of law enforcement has also become the focus of attention. In the following, the Constitutional Court shows the prominent constitutional role of precaution, while also pointing out what the principle actually means: “[20] …the legislator must also take into account the principles of precaution and prevention, since ‘failure to protect nature and the environment may trigger irreversible processes. […] [T]he legislator has a constitutional obligation to take into account the risks that, according to the scientific position, are highly likely or certain to occur with due weight in the decision.” All of this creates serious obligations for everyone – although in this case especially for the State: “[21] …taking into account the precautionary principle, the State must justify the retreat from the environmental protection level already achieved in terms of necessity and proportionality, in a substantive comparison with the enforcement of other fundamental rights” (3114/2016. (VI. 10.) AB decision, [45]).

Furthermore, a parallel strand of cases concerns noise and vibration as environmental harms that implicate health and quality of life. In Decision 3114/2016 (VI. 10.) AB, the Constitutional Court emphasised that limit values for noise and vibration are not merely technical parameters but constitutional guarantees of the right to a healthy environment. Lowering or “softening” those limits, or allowing administrative discretion to override them for convenience, risks violating Articles P) and XXI. The Constitutional Court has repeatedly distilled these themes into general constitutional requirements for the administration. Decision 4/2019 (III. 7.) AB states in clear terms that environmental and nature-protection considerations may not be relegated behind economic or other policy goals in regulatory decision-making. Rather, they occupy a constitutionally protected position that demands prioritisation where significant, possibly irreversible impacts are at stake, again echoing the precautionary and prevention principles.

In sector-specific litigation, the Court has limited deregulatory moves that threatened core conservation commitments. Decision 14/2020 (VII. 6.) AB invalidated elements of a 2017 forest law reform, holding that the protections of Natura 2000 and protected forests cannot be reduced without compelling reasons that satisfy the strict constraints of non-regression, necessity, and proportionality.11 The decision underscores that long-term ecosystem functions and biodiversity conservation are constitutional values, not discretionary policy preferences. Spatial planning around iconic natural assets has drawn similar scrutiny. In Decision 16/2022 (VII. 14.) AB on the Balaton Act,12 the Court defended public access to the shoreline (e.g., the 30-metre public strip) and reinforced green-space objectives as constitutionally relevant. Attempts to weaken the public-use guarantees or to erode green-infrastructure requirements were struck down, reflecting the Court’s view that access and ecological integrity are elements of the shared natural heritage protected by Article P). In Decision 5/2025. (VI. 30.) AB (Case II/3536/2021) an ex post review of the Climate Protection Act,13 it held that the statutory 2030 greenhouse-gas reduction target (a 40% cut from 1990 levels) was constitutionally insufficient in light of Articles P) and XXI, the intergenerational nature of climate risk, and the precautionary and prevention duties. The Court annulled the provision with delayed effect until 30 June 2026, thereby avoiding a regulatory vacuum while instructing Parliament to adopt a more comprehensive framework for mitigation, adaptation, and resilience.

 

Among the control of budget laws, it is worth highlighting Decision 18/2024. (XI. 11.) AB, in which the petitioner challenged an annex to the 2023 Budget Act.14 The AB emphasised that “the content of certain annexes to the Budget Act falls within the budgetary responsibility of the Government, in which the political decision of the Parliament is reflected”. The body therefore did not establish a violation of the Basic Law, and thus indicated: the principle of a sustainable budget primarily applies at the level of political responsibility and constitutional frameworks, while the AB’s role is limited to negative constitutional adjudication.

The stability of the revenue side was affected by the Decision 20/2021. (V. 27.) AB, in which the body decided to partially annul a local tax ordinance.15 According to the justification, “local taxation is within proportionality limits, which are also in line with the revenue stability of the central budget”. This approach shows that a sustainable fiscal path is a requirement to be enforced not only at the central but also at the local government level, and the Constitutional Court protected legal certainty and fiscal predictability through the application of the principle of proportionality. A similar logic was applied in the Constitutional Court’s Decision 3/2014. (I. 21.) AB, which annulled one of the rules of tax administration. According to the Constitutional Court,16 “regulations serving to secure budget revenues can only be adopted with constitutional guarantees”. Here, the double standard clearly appears: the sustainability aspect alone cannot override the requirements of the rule of law, so fiscal discipline must also be enforced within the framework of legal certainty.

The resolutions related to the limitations on the subject matter of referendums deserve special attention. In the Decision 11/2022. (VI. 2.) AB, the Constitutional Court explained: “decisions on the budget are a specific form of exercising popular sovereignty, which may be exercised exclusively by the National Assembly”.17 This logic was reinforced by Decisions 1/2022. (I. 7.) AB and 12/2016. (VI. 22.) AB, which also stated that issues affecting the budget cannot be the subject of a referendum. This practice is one of the most important guarantees of the principle of sustainable budgeting: it protects the long-term stability of fiscal policy by excluding the risks arising from short-term, populist referendum initiatives.

Regarding the expenditure side, Decision 25/2019. (VII. 23.) AB is worth mentioning, which examined the rules on social benefits.18 The AB pointed out: “the State’s room for manoeuvre in the area of ​​social benefits is not unlimited, it is limited by economic performance and the carrying capacity of the budget.” This statement clearly shows that the principle of fiscal sustainability is always present as a framework condition when ensuring social rights. A similar connection emerges in Decision 27/2013. (X. 9.) AB, where the AB established a constitutional requirement in connection with social law, also with regard to budgetary realities.19 In connection with the pension system, the Decision 3238/2017. (X. 10.) AB indicated: the stability of regular benefits is a fundamental right requirement, but it must be ensured within the limits of fiscal capacity.20

More distant cases, but related to public finances, include the Decision 33/2019. (XI. 27.) AB, which affected the national home-creation communities, and the Decision 3266/2018. (VII. 20.) AB, which dealt with the accounting of church subsidies.21 In these decisions, the principle of sustainable budgeting was not directly applied, but the requirement of transparent and verifiable use of public funds – which is one of the elements of Article N) – can still be recognised.