Principle of the application of the more lenient law
Non-retroactivity of criminal law
RULING Nº 150/94
8 of February of 1994
Since under the new criminal law on non-customs related tax offences types of conduct which were previously considered to be criminal offences are no longer considered as such, the law could be interpreted as being more lenient on the accused.
Although expressly mentioned in the Constitution solely in the context of criminal laws, the principle of retrospective application of more lenient criminal laws must also apply in matters of contra-ordenação (a type of offence inspired by German law and sanctioned by an administrative fine, but the decisions of which may be appealed against before the law courts).
This is a generally binding declaration of unconstitutionality, delivered following several hundred appeals concerning decisions by courts which had held that the rules in question were unconstitutional.