The Minister, where he proposes under section 207 of the principal Act (default powers) to make an order—
(a) under section 27 of that Act (revocation or modification of planning permission), or under the provisions of that section as applied by any order or regulations made under Part III of that Act; or
(b) under section 28 of that Act (discontinuance of specified use of land or alteration or removal of buildings or works),
shall serve a notice of the proposal on the local planning authority; and if within such period as may be specified in the notice (not less than twenty-eight days from the date of service) the authority so require, the Minister before making the order shall afford to the authority an opportunity of appearing before, and being heard by, a person appointed by him for the purpose.
The obligation of the Minister to serve a notice under this section shall be without prejudice to any requirements of Part III of the principal Act, or' regulations made thereunder, having effect by virtue of section 207(3) of that Act (requirements as to notice etc., where Minister acts in place of local planning authority).