What is the difference between complementary law and ordinary law?

The difference between the complementary law and the ordinary law occurs in two aspects:

  • In the field of matter, that is, what will be covered by the law;
  • In the approval quorum, which refers to how many votes are required for a law to be passed.

The complementary law will regulate the matters already reserved to it by the Federal Constitution, that is, which are already predetermined.

The ordinary law, on the other hand, will address any other matters that are not regulated by complementary law, by legislative decree or by resolutions.

Complementary law Ordinary law
Subject The complementary law addresses the matters that are provided for in the Federal Constitution. Ordinary laws may address any matters, as long as these are not reserved for supplementary law, legislative decrees and resolutions.
Approval quorum Absolute majority: more than half of all members must approve. Simple or relative majority: more than half of all those present need to approve.

Difference in approval quorum

The complementary law requires an absolute majority quorum, provided for in Article 69 of the Federal Constitution. Meanwhile, ordinary law requires a simple or relative majority quorum, which is provided for in Article 47 of the Constitution.

Initially, we must consider the quorum for the installation of the voting session, that is, how many members are necessary for voting to take place. This quorum is the same for complementary and ordinary law, and must have an absolute majority of members.

For example, if there are a total of 100 members, the absolute majority tells us that at least 51 of them must be present at the vote. Suppose there are 70 members present. Since the quorum is greater than half, voting could take place for both a supplementary and an ordinary law.

The difference is in the number of votes that each one needs to be approved.

While in the complementary law, of these members, at least 51 would need to vote yes (more than half of the 100 members, that is, the absolute majority).

In the case of ordinary law, half of those present would need to vote yes. In this case, they would need 36 votes to pass (more than half of the 70 members, who are the simple majority).


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