21.—(1) If, before the commencement of a trial at which a person is charged with an offence to which Article 19 applies, he or another person against whom the complainant may be expected to give evidence at the trial, applies to the court for a direction under this paragraph and satisfies the court—
(a)that the direction is required for the purpose of inducing persons who are likely to be needed as witnesses at the trial to come forward; and
(b)that the conduct of the applicant’s defence at the trial is likely to be substantially prejudiced if the direction is not given,
the court shall direct that Article 19 shall not, by virtue of the accusation alleging the offence in question, apply in relation to the complainant.
(2) If at a trial the court is satisfied—
(a)that the effect of Article 19 is to impose a substantial and unreasonable restriction upon the reporting of proceedings at the trial, and
(b)that it is in the public interest to remove or relax the restriction,
the court shall direct that Article 19 shall not apply to such matter as is specified in the direction.
(3) A direction shall not be given under paragraph (2) by reason only of the outcome of the trial.
(4) If a person who has been convicted of an offence and has given notice of appeal against the conviction, or notice of an application for leave so to appeal, applies to the appellate court for a direction under this paragraph and satisfies the court—
(a)that the direction is required for the purpose of obtaining evidence in support of the appeal; and
(b)that the applicant is likely to suffer substantial injustice if the direction is not given,
the court shall direct that Article 19 shall not, by virtue of an accusation which alleges an offence to which Article 19 applies and is specified in the direction, apply in relation to a complainant so specified.
(5) A direction given under any provisions of this Article does not affect the operation of Article 19 at any time before the direction is given.
(6) If, after the commencement of a trial at which a person is charged with an offence to which Article 19 applies, a new trial of the person for that offence is ordered, the commencement of any previous trial shall be disregarded for the purposes of paragraph (1).