Tijdschrift voor bestuurswetenschappen en publiekrecht vol:62 pages:259-280
An "interpretative law" is a law giving an authentical interpretation to a previous law of which the interpretation was unclear. As this interpretation is binding for both the Executive and the Judiciary, it is in fact retroactive. This retroactiveness is, however, justified: whereas a classic retroactive law goes against the principle of legal certainty, an interpretative law intents to restore this very principle. Therefore, the Constitutional Court's jurisprudence which examines whether a law called 'interpretative' is truly interpretative, is to be acclaimed.
This article inquires into the historical origins of the technique of interpretative laws, and into the theoretical foundations of this technique and of the principle of legal certainty. It then discusses the criteria developped by the Constitutional Court to assess the constitutionality of interpretative laws. These criteria have been altered by Judgment n° 102/2006, after the previous criteria had been subject to strong critiques in the doctrine. The article subscribes to the new jurisprudence.