Union officials are now receiving Section 188 notices - the first stage of the formal consultation process on job losses - but hope to be able to prevent compulsory redundancies through early retirement and redeployment. Class sizes will increase whichever way the jobs are shed, they predicted.
The Association of Teachers and Lecturers estimates that this year's total will exceed the 5,500 jobs lost in 1994. Unions said they would act swiftly against governing bodies which shed staff unnecessarily.
Tony Arthur, national executive member of the National Association of Schoolmasters Union of Women Teachers, said: "Some governing bodies are using the situation as an excuse to get rid of teachers when other savings can be made. We are already taking one school in Warwickshire to an industrial tribunal."
In Warwickshire, where last week 20 schools set deficit budgets, it is anticipated up to 200 teaching posts may be lost, amid fears of 40-plus class sizes in some areas.
Union officials in Bedfordshire predict more than 100 compulsory redundancies, and in Staffordshire, up to 300 posts could be lost. Two hundred jobs are expected to go in Leicestershire.
More than 600 posts are expected to be lost in Devon and Cornwall. Margaret Morgan, the region's executive member of the NASUWT, said: "Virtually every secondary school is being affected. Schools have already pared and pared away in the past through early retirements, so there are expected to be fewer voluntary redundancies."
In Cambridgeshire, where cuts of more than Pounds 6 million were made in the education budget, 100 protective notices have been issued. Around 20 are expected to involve compulsory redundancies.
At least 300 posts will be lost in Lancashire, where reductions of more than 5 per cent in the education budget left some schools worse off by up to Pounds 150,000.