Where on a representation made for the purpose by the person carrying on a statutory undertaking the Secretary of State is satisfied that the making of any order under or in pursuance of Part II of this Act or the giving of any direction in pursuance of the said Part II has rendered impracticable the fulfilment of any obligation of that person incurred in connection with the carrying on of the undertaking, the Secretary of State may by order direct that that person shall be relieved of the fulfilment of the obligation either absolutely or to such extent as may be specified in the order.