(1)    The Commissioners are not required under section 33 to review any decision unless the notice requiring the review is given before the end of the permitted period.

(2)    For the purposes of this section the “permitted period” is the period of 45 days beginning with the day on which the relevant notice is given.

(3)    For the purposes of subsection (2) the “relevant notice” is—

(a)    in the case of a review by virtue of subsection (1) of section 33, the notice mentioned in that subsection; or

(b)    in any other case, the demand notice in question.

(4)    Nothing in subsection (1) prevents the Commissioners from agreeing on request to review a decision in a case where the notice required by that subsection is not given within the permitted period.

(5)    A person may give notice under section 33 requiring a decision to be reviewed a second or subsequent time only if—

(a)    the grounds on which he requires the further review are that the Commissioners did not, on any previous review, have the opportunity to consider any particular facts or matters; and

(b)    he does not, on the further review, require the Commissioners to consider any facts or matters which were considered on a previous review of the decision, except in so far as they are relevant to any issue to which the facts or matters not previously considered relate.