Doctrine of Covering the Field. The concept or otherwise doctrine of covering the field by the Constitution is where the Constitution has made a provision governing an issue and a National or even State enactment goes ahead to also legislate on such an issue.
By the doctrine of covering the field, the Constitution is said to have ‘covered the field’, and to that extent, the National or State enactment on the subject, at best, becomes redundant. In furtherance of the supremacy status of the constitution, where there are other legislations on an issue which the Constitution has provided for, the provisions of the Constitution prevail.
Where the constitution has covered the field as to the law governing any conduct, the provision of the constitution is the authority of the law on the subject. However, as the Supreme Court pointed out in the case of Independent National Electoral Commission & Anor V. Alhaji Abdulkadir Balarabe Musa & 4 Ors, the Constitution would not have ‘covered the field’ where it has expressly reserved to the National Assembly or any other legislative body the power to expand on or add to its provisions in regard to the particular subject.
Where the constitution has provided exhaustively for any situation and on any subject, a legislative authority that claims to legislate in addition to what the Constitution has enacted must show that, and how it has derived its legislative authority to do so from the Constitution itself.
Thus, in considering the provisions of the Constitution of the Federal Republic of Nigeria, 1999 as to restriction on formation of political parties; and the purported Act of the national assembly on the same subject matter in the case of Independent National Electoral Commission & Anor V. Alhaji Abdulkadir Balarabe Musa & 4 Ors; the Supreme Court had this to say:
“In this case S.22 of the Constitution having set out the conditions upon which an association can function as a political party, the National Assembly could not validly by legislation alter those conditions by addition or subtraction and could not by legislation authorize the Independent National Electoral Commission to do so unless the Constitution itself has so permitted.
Doctrine of Covering the field application
The doctrine of covering the field can and will apply in two distinct situations, which are:
- Where in the purported exercise of the legislative powers of the National Assembly or a State House of Assembly a law is enacted, which the Constitution has already made provisions covering the subject matter of the Federal Acts or the State Law.
- Where a State House of Assembly, by the purported exercise of its legislative powers enacts a law which an Act of the National Assembly has already made provisions covering the subject matter of the State Law.
However, a State Law which is not necessarily inconsistent with either the Constitution or an Act of the National Assembly but merely covers the legislative field of the National Assembly is not that harmful as it is merely a surplusage.
Such a law is in abeyance and inoperative and could be revived and becomes operative if for any reason the federal legislation is repealed. See the case of A.G. Ogun State V. A.G. Federation (1982) 3 NCLR, 166; A.G. Abia State V. A.G. Federation (2002) 6 NWLR, pt.763, 264.