It's widely believed that people who maintain their innocence are treated more harshly than those who go along with the system.
But what is it like to be in prison, the victim of a miscarriage of justice and feel the only path to early release or better conditions is an acknowledgement of guilt? One person who can answer this question is Annette Hewins, who spent two years in prison for a crime she didn't commit.
Mandy English became a campaigner for Miscarriage of Justice when her son was wrongly accused of murder. Mary Cane is a member of the Parole Board. They discuss with Jenni whether it is possible there are hundreds of people in prison in a similar position to Annette's.