17.—(1) The Welsh Ministers may decide to vary a permission granted under these Regulations, in whole or in part.
(2) The Welsh Ministers may do so either —
(a)on the application of a person mentioned in regulation 18(1); or
(b)of the Welsh Ministers' own motion, in the circumstances provided for in regulation 21(1).
(3) Any variation may be made not only to the permission itself but also to any condition to which the permission was subject prior to the variation.