London: Under guidance to be outlined this week, it will be unacceptable to stop families adopting children of a different ethnic group.

This reverses current advice saying social workers must give "due consideration to the child's religious persuasion, racial origin and cultural and linguistic background". Yet ethnic minority children wait three times longer than white youngsters to find new parents and many are not adopted at all.

Last year about 20 per cent of the 2,300 children waiting to be adopted were black or Asian. The new guidance warns that delaying placing a child in a family on ethnic grounds can seriously hamper their development.