Subject to sub-paragraph (2) of this paragraph, the basic electricity rateable value shall be taken to be £47,212,610; and the share thereof of each respectively of the Electricity Boards set out in the following table shall be the percentage of that sum so set out in relation to that Board.

If it appears to the Minister that by reason of any substantial change of circumstances it is expedient so to do, he may by order made after consultation with the Electricity Council and with such associations of local authorities as appear to him to be concerned, and with any local authority with whom consultation appears to him to be desirable, vary the sum which under sub-paragraph (1) of this paragraph is to be taken to be the basic electricity rateable value ; but an order under this sub-paragraph shall not have effect until approved by a resolution of each House of Parliament.