If a request is made under subsection 64J(2) for the costing of a policy of a Parliamentary party (the first policy ), the Parliamentary Budget Officer:
(a) must ask the responsible Secretaries whether a request has been made under clause 29 of Schedule 1 to the Charter of Budget Honesty Act 1998 in relation to a policy of the Parliamentary party that is the same as, or substantially similar to, the first policy; and
(b) if a request has been made under clause 29 of that Schedule--must not prepare a costing of the first policy under this Act.