It is not possible to provide this information without incurring disproportionate costs of collection. Since the Department was formed by Machinery of Government changes on 28 June 2007 it has continued to make use of the services of several types of temporary staff, including temporaries and contractors from agencies. Such temporary staff are engaged for a variety of purposes and rates paid reflect the differences between generic and specialist services. Preferential rates of pay and terms of engagement have been negotiated with certain selected agencies under an over-arching framework agreement. This procurement process has the purpose of achieving best value for money and is used across Government.