23.6 Project Co shall not carry out any Programmed Maintenance or Unprogrammed Maintenance Works save:
23.6.1 in accordance with a Schedule of Programmed Maintenance to which no objection has been made under Schedule Part 8 (Review Procedure) or, where comment has been raised in respect of the Programmed Maintenance periods and/or time, the Schedule of Programmed Maintenance has been amended pursuant to the Service Level Specification;
23.6.2 in accordance with the procedures set out in Clause 23.8; or
23.6.3 in an emergency, in accordance with Clause 23.9.
23.7 Notwithstanding that there has been no objection to a Schedule of Programmed Maintenance, the Authority's Representative may, at any time, require Project Co to accelerate or defer any Programmed Maintenance by giving written notice to Project Co, (unless otherwise agreed) not less than twenty (20) Business Days prior to the scheduled date for carrying out such Programmed Maintenance, which notice shall set out the time and/or periods at or during which the Authority requires the Programmed Maintenance to be performed. Project Co shall notify the Authority of the amount of any additional reasonable costs which it will incur as a direct consequence of such acceleration or deferment (the "Estimated Increased Maintenance Costs") within five (5) Business Days of the receipt of the written notice advising of the requirement for an acceleration or deferment of the Programmed Maintenance. The Authority shall, within a further period of five (5) Business Days following receipt by the Authority of notification of the amount of the Estimated Increased Maintenance Costs, at the Authority's option, either confirm or withdraw its request to accelerate or defer the Schedule of Programmed Maintenance. If the Authority does not respond within this five (5) Business Day period, the request shall be deemed to have been confirmed. The Authority shall reimburse Project Co the direct and reasonable costs actually incurred by Project Co as a consequence of such acceleration or deferment up to, but not exceeding, the amount of the Estimated Increased Maintenance Costs.
23.8 If, in circumstances other than an emergency, the need arises for Maintenance Works (excluding any works of a de minimis nature in respect of which the parties have agreed this Clause 23.8 shall not apply [and excluding works carried out for the purpose of Rectification, which shall take place in accordance with the provisions of Schedule Part 14 (Payment Mechanism)]), which are not scheduled to be carried out as part of the Programmed Maintenance ("Unprogrammed Maintenance Work"), Project Co shall not carry out any Unprogrammed Maintenance Work unless and until the Authority's Representative has approved the proposed commencement date, the proposed hours of work and estimated duration of the requisite Unprogrammed Maintenance Works in accordance with the provisions of paragraph 3.9 of Schedule Part 8 (Review Procedure). Nothing in this Clause 23.8 (including any approval of the Authority pursuant to Schedule Part 8 (Review Procedure) shall prevent the Authority from making any deductions in calculating the Monthly Service Payments pursuant to the Payment Mechanism.
23.9 If, as a result of an emergency, the need arises for Unprogrammed Maintenance Works, Project Co may carry out such Unprogrammed Maintenance Works provided that Project Co shall notify the Authority's Representative as soon as possible (and in any event within [ ] Business Days of the occurrence of the emergency) of the extent of the necessary Unprogrammed Maintenance Works and the reasons for them. Project Co shall take all reasonable steps to minimise the duration of such Unprogrammed Maintenance Works. Nothing in this Clause 23.9 shall prevent the Authority from making any deductions in calculating the Monthly Service Payments pursuant to the Payment Mechanism.
23.10 Where Programmed Maintenance scheduled to be carried out in accordance with the Schedule of Programmed Maintenance has been deferred by the Authority's Representative under Clause 23.7, Project Co shall not be treated as having failed to perform the relevant Service on account of the condition of the Facilities or any part of them from the time the Programmed Maintenance was scheduled to have been completed until the time the deferred Programmed Maintenance was scheduled to have been completed, but not afterwards, provided always, to avoid doubt, that Project Co shall not be relieved from the consequences of any failure to maintain the Facilities in respect of any period prior to the period for performing the particular work according to the Schedule of Programmed Maintenance.