After the commencement
of a proceeding for the review of a decision the decision-maker cannot —
(a) vary
the decision; or
(b) set
aside the decision and substitute its new decision,
unless —
(c) that
is permitted by the enabling Act; or
(d) the
parties to the proceeding consent; or
(e) the
decision-maker is invited under section 31 to reconsider the decision.