By Gary Eason
BBC News Online education editor
Head teachers' leaders have predicted "several thousand" job losses in schools in England due to budget shortfalls.
Redundancies "only tip of the iceberg" say head teachers
John Dunford, general secretary of the Secondary Heads Association, made the prediction after the prime minister told MPs some schools had been "seriously" affected by funding problems and 500 teachers were facing redundancy.
Tony Blair said the Department for Education and local education authorities were looking at each case to see how they could help.
There are suggestions - officially denied - that efforts are being made to find more money for the worst-hit schools.
The department said later that half the cuts were deficit-related - with the others being mainly in schools where pupil numbers were falling.
Last week a survey by the NASUWT teachers' union found employers in England had dismissed 696 school staff - 237 of them because of financial problems.
John Dunford drew a distinction between the statistics on redundancies as such, and actual job losses in terms of vacated posts not being filled.
"More important than the redundancy figure is the very substantial number of job losses in schools with serious budget problems which will inevitably mean cutbacks in educational provision and an impact on standards," he told BBC News Online.
"That is, where people leave and are not replaced - and that's happening all over the country."
Every year at this time there is a large turnover of teachers, especially in the secondary sector.
"I was talking to a head the other day who told me he had 12 leaving and he was replacing eight of them," Dr Dunford said.
"It's not been in the headlines but this is happening right across the board.
"It is probably several thousand, I have no doubt."
And if, say, a maths teacher left and was not replaced, the school would probably cut the number of maths lessons on offer next year.
'Undermine the message'
His counterpart David Hart at the National Association of Head Teachers - a majority of whose members are in primary schools - also said Tony Blair's redundancy figures were "the tip of the iceberg".
"They do not take into account non-renewal of temporary contracts, or failure to fill vacancies or cuts in support staff hours, all of which are taking place on a widespread basis.
"It is also highly dangerous to imply that falling rolls excuse redundancies," he added.
He agreed that several thousand job losses was a likely figure.
He had met primary head teachers in the education secretary's Norfolk constituency on Wednesday, who had painted a very bleak picture.
One, for example, was cutting the amount of support staff time from 600 hours a year to 300 - no redundancy involved, but a significant impact on children's learning.
It was "highly damaging to the government's standards agenda".
Some sources have suggested that civil servants have been told to scour current programmes to see if they can find any money that could be used to help struggling schools.
Asked about this, Dr Dunford said: "It's essential the government finds more money this year otherwise this year's problems will continue into next year's budgets and we shall have two years of reduced provision."
David Hart said he "wouldn't put any money on the government producing any extra this year".
He said: "It is abundantly clear that if the government does not produce a significantly better funding deal for the next two years, the level of redundancies seen this year will be like a children's tea party."
A spokesperson at the education department said there would be no more money. It was looking with education authorities at what could be done within the resources already in the system.