If:
(a) a person who is a member of a couple is receiving parenting payment; and
(b) as a result of a social security pension, a service pension, income support supplement or a veteran payment becoming payable to the person, the rate at which parenting payment is payable to the person is reduced;
parenting payment becomes payable to the person at the reduced rate on the day on which the social security pension, the service pension, the income support supplement or the veteran payment, as the case may be, becomes payable to the person.