122.—(1) If at any time after the completion of a specified work, not being a work vested in Network Rail, Network Rail gives notice to the undertaker informing it that the state of maintenance of any part of the specified work appears to be such as adversely affects the operation of railway property, the undertaker must, on receipt of such notice, take such steps as may be reasonably necessary to put that specified work in such state of maintenance as not adversely to affect railway property.
(2) Regardless of anything in sub-paragraph (1), on receipt of a notice given by Network Rail pursuant to sub-paragraph (1), the undertaker may respond in writing to Network Rail requesting Network Rail to take the steps as may be reasonably necessary to put the specified work the subject of the notice in such state of maintenance as not adversely to affect railway property. If Network Rail agrees to undertake the steps it must give to the undertaker reasonable notice of its intention to carry out such steps, and the undertaker must pay to Network Rail the reasonable cost of doing so.