6.—(1) The Board shall, on or before such date in each year as the Department may direct, submit to the Department, in such form and containing such particulars as the Department may direct, an estimate of its income and expenditure for the succeeding financial year.
(2) The Board may at any time submit a supplementary or revised estimate to the Department.
(3) The Department may approve an estimate submitted under paragraph (1) or a supplementary or revised estimate submitted under paragraph (2) either in whole or in part or subject to such modifications or conditions as the Department may think fit.
(4) The Board shall not incur expenditure otherwise than in accordance with an estimate or a supplementary or revised estimate approved under paragraph (3).