David Blunkett has warned that pre-teen offenders could face custodial sentences in plans to be included in a white paper later this year.

However, the Howard League for Penal Reform yesterday lodged papers with the High Court against government plans to exclude children in custody from the 1989 Childrens Act.

Metropolitan Police Commissioner Sir John Stevens cautioned that clamping down on mugging and robbery could see hundreds of black men convicted, leaving them unemployable and increasing the chances of them turning to a life of crime.