The pilots will begin in October.

Changes to the youth justice system include warning schemes, reparation orders, "action plan" orders, child safety orders, parenting orders and youth offending teams, and will be piloted in nine areas.

Lord Irvine said the 18-month youth justice pilots "will help develop good practice and allow us to assess the costs and savings which nationwide implementation will involve. The pilots will inform decisions over the timing of full implementation of these measures.

"Experience from these pilots and other area-based initiatives will help to ensure new measures are implemented effectively at local level."

The areas piloting the changes will include Hammersmith & Fulham, Kensington & Chelsea, Westminster, Hampshire, Portsmouth, Southampton and Wight, Wolverhampton, and Sheffield.

Another five areas will be piloting child safety orders, parenting orders and youth offending teams only. They are: Lewisham, Bedfordshire and Luton, Devon, St Helens, and Sunderland.

Procedural changes to reduce court delays will be piloted in Tyneside, Croydon, Blackburn and Burnley, Northamptonshire, North Staffordshire, and North Wales.

Blackburn and Northants will also be piloting final warning schemes and youth offending teams.