19. Supplementary approval required: In addition to the approval of the regional council in question, the acceptance of a tender by a public institution must also be subject to the approval in writing of the Minister in the following cases:(1) where the tender selected is not the lowest complying with the conditions;
(2) where the tender is obtained under a proposal for the leasing of space covered by paragraph 1, 2 or 3 of section 6;
(3) where, following an invitation to tender, only one tender complying with the conditions is received.