The Office for National Statistics publishes Civil Service employment statistics every quarter in the Public Sector Employment First Release. The latest statistics published are for Q4 (December) 2007. These can be viewed at:
Table 6 of the publication provides a breakdown of employment by Government Department. This has been available since Q1 2006, and since Q4 2006 it has included a breakdown of permanent and temporary/casual employees. Links to the on-line publications can be viewed at:
Prior to 2006 Civil Service employment numbers were available on only an annual basis. A link is provided to the Civil Service statistics on the Cabinet Office website:
Civil Service statistics collected are the number of employees and not the number of posts. An employee covering multiple posts is counted only once and no information on vacancies is held.
The ONS does not publish statistics for non-Civil Service posts broken down by Government Department.
Information on employment agency workers could be provided only at disproportionate cost.