Detailed information on all staff, including children’s social workers, directly employed by social services departments is collected through the Personal Social Services staff of Social Services Departments return (SSDS001) which was introduced in 1993 by the Department of Health. In 2004-05 responsibility for the collection of this data passed to the NHS Information Centre for health and social care. These data have been published on an annual basis with breakdown by local authority available in the supporting annexes published alongside each report.
Reports published from 2006 onwards are available on the NHS Information Centre website here:
http://www.ic.nhs.uk/statistics-and-data-collections/social-care/childrens-social-care
Reports published between 1996 and 2005 are available on the Department of Health website here:
http://www.dh.gov.uk/en/Publicationsandstatistics/Statistics/StatisticalWorkAreas/Statisticalworkforce/DH_4000233