The available information is given in the following table.
Average class size Key stage 1 classes4 25.6 Key stage 2 classes 27.3 Classes in primary schools 26.3 Classes in secondary schools 21.5 1 Classes as taught during a single selected period in each school on the day of the census in January. 2 Classes taught by one teacher. 3 Provisional. 4 Includes reception classes. Source: Schools’ Census
Final 2006 class size data will be published in September.
The information provided in this response was published in April in the Statistical First Release: Pupil Characteristics and Class Sizes in Maintained Schools in England, January 2006 (Provisional):
http://www.dfes.gov.uk/rsgateway/DB/SFR/s000654/index.shtml