10E+W+SIf at any time it appears to the local authority that for a period of not less than two years the person, or each of the persons, who was for the time being during that period the holder of a licence in respect of a licensed parking place has made available to the public at that parking place a substantially lower number of parking spaces than that authorised by the licence, then, subject to paragraph 13 below, they may by notice in writing to the holder of the licence vary the terms and conditions of the licence specified under section 43(4)(b) and (c) of this Act so as to authorise the provision at the licensed parking place of only that number of parking spaces which it appears to the local authority was being provided at the date of the notice.