When considering taking a decision to deregister, the Director referred to in article R. 5312-26 shall inform the person concerned in advance, by any means giving a date certain, of the facts of which he or she is accused and of the duration of the proposed deregistration, indicating that he or she has ten days in which to submit written observations or, if he or she so wishes, to ask to be heard, if necessary assisted by a person of his or her choice.