A top government expert has said that some three-year-old children in Britain spend so much time in front of the TV that they appear to be unable to walk.
Louise Casey, Prime Minister David Cameron's adviser on troubled families, said a teacher informed her that one child spent so much time alone in front of the TV screen that he could not even chew.
Casey said the problem of young children being unable to walk was a clear sign of the height of the challenge to help around 120,000 troubled families in the country, the Daily Mail reported.
National Association of Head Teachers general secretary Russell Hobby said it was an extreme case, "but more frequently we hear of children who can't speak when they come to school".
He said those children can "only grunt" while some still wear nappies at the age of five.
A playschool creator earlier warned that parents should avoid leaving young children unsupervised in front of the TV.