reg 59 Change of plea
(1) At any time before the lay members withdraw to deliberate on their finding on a charge, a defendant who has pleaded not guilty to the charge may withdraw his plea and substitute a plea of guilty. (2) But a judge advocate may not accept a plea of guilty substituted under paragraph (1) unless satisfied that the defendant understands the matters mentioned in rule 56(3). (3) At any time before the court begins to deliberate on its sentence for an offence, a defendant who has pleaded guilty to the charge of the offence may, with the leave of a judge advocate, withdraw his plea and substitute a plea of not guilty. (4) Where a defendant changes his plea under paragraph (3)— (a) in the course of sentencing proceedings in relation to the offence, or (b) in the course of trial proceedings in relation to another charge, the judge advocate shall terminate the proceedings.