Right of attendance of President
Section 67(2) · 1999 Constitution (2004 edition)
What Constitution says
(2) A Minister of the Government of the Federation attend either House of the National Assembly if invited to express to the House the conduct of his Ministry, and in particular when the affairs of that Ministry are under discussion.
This is the 1999 Constitution as published in 2004. Later amendments aren't included yet, so a section may have changed since.
Original source
Official Gazette · CFRN 1999 official PDF · printed page 48–49. Original document
Release: draft-c8d50d87fae9. Source scope, review and corrections