Separation of Powers in Nigeria: Theory, Practice and the Space Between

Sections 4, 5 and 6 of the Constitution of the Federal Republic of Nigeria 1999 (as amended) vest legislative, executive and judicial powers in three distinct arms of government. On paper, the arrangement is a classical Montesquieuan model: the National Assembly makes law, the President executes it, and the courts interpret it. In practice, Nigerian constitutional life is a running negotiation over where one arm ends and another begins.

Where the doctrine holds

The clearest expression of the doctrine remains the judiciary's power of review. In Attorney-General of Abia State v. Attorney-General of the Federation, the Supreme Court confirmed that it will strike down legislation that exceeds constitutional competence, regardless of how politically expedient the statute may be. Similarly, the courts have consistently refused to allow the legislature to exercise judicial functions. A legislative committee may investigate under section 88, but it may not convict, fine or imprison.

Where it strains

Three pressure points recur.

The first is executive law-making. Ministerial regulations, executive orders and agency guidelines have proliferated, and many go well beyond the parent statute. Delegated legislation is constitutionally permissible, but only within the four corners of the enabling Act. Where an executive instrument creates offences or imposes levies that Parliament never authorised, it is ultra vires and liable to be struck down.

The judicial funding question

Second is the funding of the judiciary. Section 81(3) requires that amounts standing to the credit of the judiciary be paid directly to the National Judicial Council. The practical reality of state-level judicial funding has, for years, fallen short of that provision, and the Supreme Court's decision in Olisa Agbakoba v. Attorney-General of the Federation affirmed the principle of financial autonomy. Financial dependence is a quiet but powerful constraint on judicial independence.

Third is legislative oversight that shades into administration. Oversight is a legitimate legislative function; directing the day-to-day operations of an agency is not.

Why it matters for practice

For a litigator, separation of powers is rarely the headline argument. It is more often the structural point that decides whether a claim is justiciable at all. Where a matter is genuinely committed to the political branches, the courts will decline to intervene. Where a rights question is engaged, however, the political-question label offers no shelter: section 46 gives the High Court original jurisdiction over fundamental rights claims, and a court cannot decline that jurisdiction merely because the respondent is a political actor.

Conclusion

Separation of powers in Nigeria is best understood not as three sealed compartments but as three overlapping domains policed by the courts. The doctrine does its real work at the margins, in cases where one arm reaches into another's territory and someone with standing objects. For the student and the practitioner alike, the value of the doctrine lies less in its symmetry than in its usefulness as a tool for testing the limits of official power.