3E+W+SWhere a notice has been given under paragraph 2 above by a relevant undertaker to the operator, the operator may within the period of 10 days beginning with the giving of the notice give the relevant undertaker a counter-notice which may state either—
(a)that the operator intends himself to make any alterations made necessary or expedient by the proposed undertaker’s works; or
(b)that he requires the undertaker in making any such alteration to do so under the supervision and to the satisfaction of the operator.