Preamble

Political parties constitute a particularly important form among associations of a political nature. The natural development of the associative process in Portugal immediately imposed the existence of political parties as a political fact. The necessity to create conditions which, in an institutional manner, perfect the democratic means by which citizens may participate in political life has made it imperative to immediately regulate that associative form. Political parties have already revealed - when effectively prepared to assume the charges and responsibilities of government - their capacity for mobilization and intervention in the political life of the country.
Since party action must be executed without ambiguity or equivocation which disturbs the common good of citizens, various obligations are envisioned in respect of publicity, and it is hoped that, accordingly, political life will gain clarity and citizens will gain knowledge as to the ends and means which each party proposes: that is to say, that they will gain in freedom.
The parties shall benefit from fiscal exemptions, corollary to the recognition of the importance and meaning of their action in political life. However, these exemptions will only be maintained if the party effectively represents a reality from an electoral viewpoint.
The freedom of the national parties to associate with related parties, or their affiliation with international organizations, is naturally subject to the limitations imposed by the need to safeguard their independence, which is demanded as a result of their right to political participation in the functioning of sovereign bodies.
On these terms:
Using the faculty conferred by Paragraph 1, Section 3, of Article 16 of Constitutional Law No.3/74, of 14th May, the Provisional Government decrees, and I promulgate as law, the following: