4.19—(1) Subject to rule 4.17(2), a document which has been filed or served in proceedings to which this Part applies, may not be amended without the leave of the court which shall, unless the court otherwise directs, be requested in writing.
(2) On considering a request for leave to amend a document the court shall either–
(a)grant the request, whereupon the proper officer shall inform the person making the request of that decision, or
(b)invite the parties or any of them to make representations, within a specified period, as to whether such an order should be made.
(3) A person amending a document shall file it and serve it on those persons on whom it was served prior to amendment; and the amendments shall be identified.