Dalam hal pelaksanaan “preliminary review”, maka putusan pengadilan menguji suatu ketentuan RUU. Pada konteks ini tidak ada sarana atau pernyatan pembatalan; sehingga tidak perlu pengundangan putusan tersebut (misalnya di Prancis dan Italia). Dalam hal bagian tertentu dari suatu ketentuan UU yang dibatalkan, maka bagian itu yang tidak lagi berlaku mengikat atau dalam hal kasus tertentu seperti bagian dari norma pada suatu perjanjian internasional (treaty) dinyatakan inkonstitusional, maka norma yang bersangkutan tidak menjadi bagian ketentuan yang diratifikasi. Di Prancis mekanisme ini dianut, sehingga jika ada suatu ketentuan UU yang dinyatakan inkonstitusional, maka Presiden terlebih dahulu harus menyusun perubahan norma tersebut sebelum diundangkan.
Dalam hal pengujian “ex post facto review”, maka suatu norma dalam UU dinyatakan inkonstitusional sehingga tidak berlaku mengikat dan putusan itu bersifat “erga omnes.” Pernyataan tidak berlaku itu terhitung sejak tanggal diucapkan atau pengumuman putusan tersebut (ex nunc effect). Suatu variasi diterapkan di Bulgaria, bahwa putusan semacam itu berlaku 3 hari setelah pengundangan oleh pejabat perundang-perundangan. Suatu efek putusan yang bersifat retroaktif (ex tunc effect) merupakan suatu pengecualian. Dalam hal ini, “invalidation of a legislative measure does not apply only to the pending proceedings and to proceedings under way at the date of the judgment, but also to certain proceedings which have already been closed.”
Di Belgia, “where judgments by the Court of Arbitration have effect ex tunc; nonetheless, the Court may indicate which effects of provisions that have been set aside must be considered irreversibly cancelled and which effects are maintained provisionally for a period which it specifies.” Sementara itu, di Portugal, “the principle of res judicata is maintained; the Constitutional Court may order an exception to this principle, in particular in criminal matters.” Sementara itu, di Irlandia, “where the courts may however limit the retroactive effect to persons who had brought court proceedings at the date of the judgment.”
Di negara lain, MK diperkenankan menetapkan putusan yang retroaktif, seperti di Ardora dan Yunani. Di Jerman, “judgments in criminal matters which are based on an unconstitutional provision may be revised; other decisions are no longer capable of being carried out.” Sementara itu di Spanyol, “Constitutional Court have retroactive effect where the non-application of the unconstitutional provision would have resulted in a less severe criminal or administrative sanction or no sanction at all.” Di Slovenia, “the Constitutional Court may determine that a judgment is to have retroactive effect where regulations adopted for the exercise of public powers are annulled; a party adversely affected by a decision adopted on the basis of such a measure is entitled to seek the amendment or annulment of such measure, provided that it was adopted less than one year before.” Dalam praktik di Hongaria, putusan yang bersifat retroaktif dimungkinkan, “where required on grounds of legal certainty; the Constitutional Court will order the reopening of criminal proceedings which resulted in a sanction based on an unconstitutional provision where its adverse effects subsist.”
Di Italia, keberlakuan putusan MK dalam keadaan tertentu ditentukan dalam praktik. Sementara itu, di Amerika, “the Supreme Court may, in certain cases, allow a reasonable time for carrying out its decisions, as in the case of the well-known judgment in Brown prohibiting racial segregation in schools.” Pada sisi lain, ketentuan di Romania menegaskan bahwa “a finding of unconstitutionality in a case of concrete review constitutes legal grounds for a retrial in civil cases, at the request of the party that claimed the exception of unconstitutionality, and in criminal cases in which the conviction was based on the provision declared unconstitutional.”
Di sejumlah negara, putusan MK dapat diperintahkan untuk ditunda pelaksanaannya guna memberikan kesempatan kepada otoritas legislasi supaya mengubah UU untuk menyesuaikan dengan putusan tersebut. Keadaan tersebut dimungkinkan dalam hal: (i) “where several solutions consistent with the Constitution are possible”; (ii) “the effects of judgments are deferred in particular where the judgment has major budgetary implications (for example in the field of tax or social security benefits)”; dan/atau (iii) “where it requires administrative reorganizations.” Sebagai contoh, ketentuan Konstitusi Polandia mengatakan bahwa, “the Court may determine another date for the extinction of the binding force of the legislative measure. This time may not exceed 18 months in the case of a law and 12 months in the case of other legislative measures.” Sementara itu, di Slovenia diatur bahwa “judgments of the Constitutional Court are declaratory where they make a finding that there has been a legislative omission or that the unconstitutionality cannot be remedied by annulling or abrogating the contested measure; in such case, the Court sets a period for the competent authority to rectify the unconstitutionality.” Kondisi lain berlaku di Republik Ceko di mana “the Constitutional Court is even at liberty to determine the date on which its judgments take effect.”
Pada sisi yang lain, putusan MK dapat saja merubah atau menambahkan ketentuan yang ada sebagai norma dalam UU. Di Italia, “the Constitutional Court sometimes gives judgments which result in the scope of a provision being extended to cover persons who have suffered unjustified discrimination or which add provisions directly derived from the Constitution to provisions declared unconstitutional on the ground that they fail to implement the Constitution fully.” Dalam kasus yang sama, ketentuan Konstitusi Romania menegaskan bahwa “for a specific institution in the framework of abstract preliminary review: the Court’s judgment has the effect of a suspensory veto, in that the unacceptable provision is sent back to the Parliament to be reexamined.” Selanjutnya, terkait dengan implikasi terhadap perubahan konstitusi, diatur bahwa “Parliament is thus authorised to derogate from the Court’s decision by the same majority as that which allows the revision of the Constitution; however, such a revision is not possible without a referendum the reexamination procedure is therefore not equivalent to a revision of the Constitution.”
Mayoritas negara mengumumkan putusan MK secara formal. Putusan MK Bosnia dan Herzegovina diumumkan pada “the Official Gazettes of Bosnia and Herzegovina and its constituent entities.” Demikian pula putusan Special Supreme Court di Bulgaria, Estonia, Hongaria, Italia, Prancis, dan Yunani. Di Polandia, “judgments are published in the organ in which the contested measure was promulgated and, in the absence of such an organ, in the official gazette.” Di negara lain, misalnya Kanada, publikasi itu menyatu dalam laporan tahunan kinerja pengadilan yang bersangkutan. Namun demikian, laporan seperti itu kadang-kadang hanya memuat suatu putusan tertentu saja, seperti yang dilaksanakan di Yunani, Irlandia, dan Korea Selatan.
Pelaksanaan putusan MK terhadap kewenangan lembaga lain beraneka ragam. Di Prancis, oleh karena sifatnya “constitutional preview”, maka putusan Dewan Konstitusi tidak perlu diundangkan. Situasi serupa dilaksanakan oleh negara yang mengadopsi “abstract review” yang ditujukan kepada suatu RUU, seperti di Bulgaria, Estonia, dan Turki, bahkan dapat berupa perintah langsung dari MK seperti di Kanada, Filandia, dan Republik Ceko. Di Albania, “in principle judgments of the Constitutional Court have no effect on other authorities except where they determine the competent authority in a particular case.”
Mayoritas dampak putusan MK terhadap otoritas lembaga lain menyangkut perintah pengundangan putusan oleh eksekutif seperti di Austria dan Indonesia. Dampak lain adalah perintah—bagi kategori jenis legislasi tertentu—untuk memperhatikan ketentuan konstitusi (Jepang, Lithuania, Moldova, dan Belanda). Di Slovaka, “the legislature has to bring the legislation into line with the Constitution within a period of six months of the decision of the Constitutional Court.” Di Republik Ceko, “that enforceable decisions of the Constitutional Court are binding on all authorities and persons.” Sementara itu, di Italia, Jaksa Agung “orders the release of anyone detained on the basis of an unconstitutional law.”
Di negara lain, bentuk pelaksanaan putusan MK berupa perintah pembebasan terdakwa dari tahanan, misalnya di Swiss. Kemudian, bentuk lain adalah memerintahkan badan legislatif untuk mengubah ketentuan UU seperti di Korea Selatan dan Hongaria. Selanjutnya, di Hongaria, pelaksanaan putusan MK berupa “ordering the reopening of criminal proceedings which gave rise to a sanction with continuing adverse effects.” Di Slovenia, “where necessary, the Constitutional Court shall specify the institution responsible for the implementation and the conditions for applying the decision.” Di Ukraina, “may specify in its decision or its opinion the procedures to be followed in order to give effect to them and compel the competent institutions of the State to carry out the decision to comply with the opinion.” Pada negara lain, pengadilan konstitusi dapat memperluas wewenangnya dengan memerintahkan badan-badan lain guna melaksanakan tindakan-tindakan tertentu seperti di Irlandia dan Malta. Di Amerika, bahkan MA dapat memerintahkan sanksi tertentu jika putusannya diabaikan.
Pasal 62 ayat (1) Konstitusi (1958).
Pasal 127 Konstitusi.
Venice Commission, “Decisions of Constitutional Courts and Equivalent Bodies and Their Execution”, Report adopted by the Commission at its 46th plenary meeting, 9-10 March 2001, hlm. 13.
Ibid.
Ibid.
Pasal 8 Special Law on the Court of Arbitration.
Pasal 282 Konstitusi Portugal.
Venice Commission, “Decisions of Constitutional Courts…”, op.cit., hlm. 14.
Pasal 79 UU MK Jerman ( Law on the Constitutional Court).
Pasal 40 UU Organik MK Spanyol (Organic Law of the Constitutional Court).