21.9—(1) When a child who is not a patient reaches the age of 18, a litigation friend’s appointment ceases.
(2) When a party ceases to be a patient, the litigation friend’s appointment continues until it is ended by a court order.
(3) An application for an order under paragraph (2) may be made by—
(a)the former patient;
(b)the litigation friend; or
(c)a party.
(4) The child or patient in respect of whom the appointment to act has ceased must serve notice on the other parties—
(a)stating that the appointment of his litigation friend to act has ceased;
(b)giving his address for service; and
(c)stating whether or not he intends to carry on the proceedings.
(5) If he does not do so within 28 days after the day on which the appointment of the litigation friend ceases the court may, on application, strike out(GL) any claim or defence brought by him.
(6) The liability of a litigation friend for costs continues until—
(a)the person in respect of whom his appointment to act has ceased serves the notice referred to in paragraph (4); or
(b)the litigation friend serves notice on the parties that his appointment to act has ceased.