CHAPTER FOUR –– THE BILL OF RIGHTS
Part 2—Rights and fundamental freedoms
50. Fair hearing.
(2) Every accused person has the right to a fair trial, which includes the right—
(p) to the benefit of the least severe of the prescribed punishments for an offence, if the prescribed punishment for the offence has been changed between the time that the offence was committed and the time of sentencing ;
EDIT.