Without prejudice to section 18, the Authority, in determining the remuneration or allowances for expenses to be paid to members of its staff or the other terms or conditions subject to which such members hold or are to hold their employment, shall comply with the Government or national agreed guidelines which are for the time being extant or to Government policy concerning remuneration and conditions of employment which is so extant and, in addition to the foregoing, the Authority shall comply with any directions with regard to such remuneration, allowances, terms or conditions which the Minister with the agreement of the Minister for Finance may give.