5.—(1) For the purposes of section 18A of and Part I of Schedule 4 to the Act, a lessor is to be taken to have withheld his consent unreasonably where paragraph (2), (3) or (4) applies.
(2) This paragraph applies where –
(a)the lease provides that consent shall or will be given to an alteration of the kind in question; and
(b)the lessor withholds his consent to the alteration.
(3) This paragraph applies where –
(a)the lease provides that consent shall or will be given to an alteration of the kind in question if it is sought in a particular way;
(b)it is sought in that way; and
(c)the lessor withholds his consent to the alteration.
(4) This paragraph applies where the lessor is taken to have withheld his consent by virtue of regulation 4.