Hounslow Council has been named in a report by Kent child protection committee which revealed how more than half the total of children in care in Kent have come from outside the authority, mainly from London boroughs, in a practice branded "dumping" by Thanet North Conservative MP Roger Gale.

Most are concentrated in children's homes and foster families in the Isle of Thanet, the easternmost part of the county furthest from the Capital and a district already facing severe economic and social deprivation, according to the committee's board of inquiry. Numbers are highest in the poorest wards in and around Margate, where police and health workers are among those highlighting crime and other problems caused by the highly transient population.

The report, outlined by The Guardian's Social Affairs Correspondent, warns of a "community at tipping point, where this explosive mixture will have potentially serious consequences for those people who are placed there and the local communities, unless fundamental measures are taken now".

The findings are a blow to the government, which has been calling on local authorities for some seven years to place children in care - termed looked-after children - close to their home communities wherever possible. The 1997 Utting report, on children living away from their parents, recommended that looked-after youngsters should be as close to "home" as possible, and guidelines suggest a 20-mile limit. However, there is still nothing to stop councils making arrangements with private fostering agencies to place children out of their area, with no requirement to do more than notify the receiving authority.

Hounslow and Islington Councils placed the highest numbers of children in Thanet as at July last year.  Both councils have stated that they were trying to increase numbers of foster families locally to help cut out-of-borough placements.

The children's minister Maria Eagle said that the government had introduced local authority targets stressing the importance of stability for children in care, and was finishing a project looking at ways to help councils find places for children nearer home