Eammon O'Kane, general secretary of the National Association of Schoolmasters Union of Women Teachers, said early indications of his union's own redundancy survey tallied with the TES's findings that shrinking rolls were a major factor.
"So far we have had difficulty identifying large numbers of redundancies specifically related to the funding issues," he said.
But he stressed that this would not be the case in all areas and that the prospect of more than 1,000 job losses, identified in The TES survey, would represent a significant problem. With schools sitting on reserves of more than pound;1.14 billion, he said, it was unacceptable that any teacher should be threatened with the sack and the NASUWT would vigorously fight every case.
Martin Ward, Secondary Heads Association deputy general secretary, said the number of posts lost through natural wastage was a better indicator of funding problems because schools usually managed to avoid actual redundancies.
"If there are 1,000 people being made redundant then there will be several thousand who will leave without being replaced," he said.
Referring to the downward trend in primary vacancies (see graph, left), Mr Ward said: "There are still advertisements up all over the country encouraging people to go into teaching but trainee teachers will feel cheated and the rest of us should as well."
Schools minister David Miliband is to address a governors' conference on funding tomorrow by video link. Neil Davies, chairman of the National Governors' Council, said: "If we have not got the money, we cannot provide the schools or the educational standards that the Government is leading parents and students to expect."