I could find little on the
http://www.teachernet.gov.uk website to absolutely confirm this apart from this document, which a Staffing Protocol document produced by Liverpoll City Council that mentions it in passing.
http://www.teachernet.gov.uk/_doc/8256/Liverpo ol_staffing_protocol.doc
Maybe because I wasn't willing to register with the site that I was limited to what I could access.
The ATL publishes what I found to be an excellent document on teacher redundancy. You can download it here.
http://www.atl.org.uk/atl_en/images/Redundancy %202007_tcm2-1677.pdf
It mentions that the conditions of a teacher's employment conditions in a maintained school (i.e. public-sector) only allow for termination of contract at the end of a term, and I suspect these dates are either 31 December, 30 April or 31 August - it is built into teacher's employment contracts. All the examples in the booklet are based upon one of these dates. However if you are a member of the support staff, kittysas, look at para 64 because these dates may not apply to you.
Sorry about my initial assumptions being wrong - we live and learn. BM