Any increase of jobseeker's allowance payable under section 142(1) in respect of a qualified child who normally resides with the claimant or beneficiary and with the spouse, civil partner or cohabitant of the claimant or beneficiary shall be payable at the rate of one-half of the appropriate amount in any case where the spouse, civil partner or cohabitant of the claimant or beneficiary
(a) is not a qualified adult, or
(b) is a spouse, civil partner or cohabitant referred to in section 141(2) (d),
and section 142(1) shall be read and have effect accordingly.