(1) In this section "a request to which this section applies" means a request under section 7 to which section 26(3) or 27(3) applies or to which section 28(5) applies and which, apart from this section, would fall to be granted.
(2) Subject to subsection (5), before deciding whether to grant a request to which this section applies, a head shall, not later than 2 weeks after the receipt of the request -
(a) if the request is one to which section 26(3) applies, cause the person who gave the information concerned to the public body concerned and, if the head considers it appropriate, the person to whom the information relates, or
(b) if the request is one to which section 27(3) or 28(5) applies, cause the person to whom the information relates,
to be notified, in writing or in such other form as may be determined -
(i) of the request and that, apart from this section, it falls, in the public interest, to be granted,
(ii) that the person may, not later than 3 weeks after the receipt