(1) Working family payment shall be payable for a period of 52 weeks (or such other period as may be prescribed) beginning on the date on which it is receivable in accordance with regulations and, except where regulations otherwise provide, the weekly rate of working family payment payable shall not be affected by any change of circumstances during that period.
(2) Where working family payment is payable in respect of a particular family for any period, no person who was included in that family at the beginning of that period shall be regarded as a member of any other family during that period.