The union's findings come at the same time as the Government is seeking ways to attract new entrants to the profession.
"Mr Blunkett is naming, blaming and shaming local education authorities for not passing on money to schools," said general secretary Peter Smith.
"The local authorities say it is because the money isn't there. But all teachers can do is contrast what the Government is saying about investing megabucks in education and looking at the redundancy notice in their hand. That is no way to raise morale."
The ATL surveyed a third of schools in England and Wales in May, and found that 5 per cent of them had been served Section 188 (redundancy) notices - one in 10 secondaries and one in 20 primaries. The association then asked how many job losses the schools expected. Extrapolated nationally, this was equivalent to 2,051 teaching posts.
The survey found schools were digging into their reserves to avert teacher job losses, were not renewing fixed-term contracts, and were shedding support staff.
Reasons given were: falling rolls, budget cuts coupled with insufficient money from Fair Funding, and redundancies due to the "fresh start" policy.
Brian Waggett, ATL member from Sefton borough council, said: "Class size reduction policy has given huge amounts to two primary schools to build extra classrooms and reduce the intake numbers of all other schools. The result is the two popular schools now take over 900 pupils while the rest crumble."
Joe Boone, from the National Association of Schoolmasters Union of Women Teachers, said his union has taken three ballots for industrial action over redundancies, plus a ballot due to a "fresh start" at Marina school, Brighton. The union has four outstanding ballots on working times and conditions of service.
National Union of Teachers' regional officers reported pockets of redundancy problems. Gethin Lewis, NUT Wales secretary, said he expected at least 200 teachers to lose their jobs this year on top of more than 1,000 who have gone since 1997. The union will be pushing for a review of funding by the new national assembly.
The NUT is balloting its members in five disputes, including the loss of an ethnic minority teacher's job, the loss of early retirement opportunities, and problems in two schools over teachers' bureaucratic workloads.
* Tomlinscote comprehensive in Camberley is losing eight teachers - two through compulsory redundancy - after a budget squeeze. The oversubscribed 1,540-pupil school is some pound;195,000 short of its pound;3.3 million budget.
* Crown Woods School in Eltham, south-east London, was closed by a one-day strike last month as NUT members protested against the loss of 18 teaching posts, aimed at reducing a pound;500,000 budget deficit.