68.—(1) The Department may issue a notice (in this Order referred to as an “enforcement notice”) where it appears to it—
(a)that there has been a breach of planning control; and
(b)that it is expedient to issue the notice, having regard to the provisions of the development plan and to any other material considerations.
(2) A copy of an enforcement notice shall be served—
(a)on the owner and on the occupier of the land to which it relates; and
(b)on any other person having an estate in the land, being an estate which, in the opinion of the Department, is materially affected by the notice.
(3) The service of the notice shall take place—
(a)not more than 28 days after its date of issue; and
(b)not less than 28 days before the date specified in it as the date on which it is to take effect.]