Rule 6—(1) Any creditor to whom notice has been given under rule 5 (8) and who objects to any debt included in the list furnished by the debtor shall, not less than 7 days before the day of hearing, give notice of his objection, stating the grounds thereof, to the court officer, to the debtor and to the creditor to whose debt he objects.
(2) Except with the permission of the court, no creditor may object to a debt unless he has given notice of his objection under paragraph (1).