The two-year pay freeze for public sector workers raises the spectre of mass industrial action by teachers, all three major classroom unions have warned.
Christine Blower, general secretary of the NUT, said her union would give "serious consideration" to action if the halt on wage rises was coupled with an expected attack on pensions and education budgets.
Leaders of the other major unions, who are currently sounding out members, have not ruled out co-ordinated strike action if a review of public sector pensions increases employee contributions or axes the final salary scheme.
Chancellor George Osborne announced the two-year freeze in his emergency Budget this week after previously saying pay rises would be pegged for just one year.
He also announced 25 per cent funding cuts across all government departments for the next four years, although sources said education could be shielded from the worst of the cutbacks.
NASUWT general secretary Chris Keates said teachers would be "very, very angry" if job losses and a potential blow to pensions accompanied the pay freeze.
She argued that teachers should be exempt from the review as their pensions had already come under scrutiny in 2006, when the retirement age was raised to 65 for new entrants to the profession.
Mary Bousted, general secretary of the Association of Teachers and Lecturers, said there would be a "strong possibility" of strike action, especially if ministers also attacked teachers' pensions.
She expressed concern about the effect of pay cuts on recruitment and retention in schools after more than a decade of improved wages.
Ms Blower said: "The combination of a proposed pay freeze, attack on pensions and significant cuts mean that we would have to give serious consideration to industrial action being part of our strategic plan at an appropriate time."
The last national industrial action over pay was in 2008, when the NUT went on strike, but the other teaching unions did not join the action.
However, the Government has staved off the full impact of union fury this year by announcing it will be honouring a commitment to a 2.3 per cent pay rise this September, meaning pay will not be frozen until 2011.
Meanwhile, headteachers' unions have demanded "clarity" on what the funding cuts will mean for frontline education so they can plan staffing and avoid redundancies.
Malcolm Trobe, policy director for the Association of School and College Leaders, said he expected more detail during the comprehensive spending review in the autumn.
"What would make our lives very difficult are piecemeal decisions," he said. "We will be asking for clarity to give headteachers the maximum opportunity to carefully and strategically plan."
He said heads would "never say never" on strike action over cuts, although previous action - over funding for the upper pay spine - was called off.
Support staff unions, which do not have an existing pay deal, have expressed concern that a small flat-rate pay rise for around 90 per cent of the country's 600,000 support staff will be inadequate. Local government workers have already suffered from a pay freeze this year.
Christina McAnea, head of education at Unison, said a proposal to give a rise of just pound;250 to all workers earning under pound;21,000 went "no where near" making up for the current five per cent inflation rate.
Higher earners, such as school business managers, will not receive anything extra.
General reaction to this week's emergency the budget from teaching unions was bitter, as teachers' leaders said the public sector was being wrongly blamed for the state of the budget deficit.
Anti-public sector rhetoric had made teachers feel like they couldn't speak out for better pay, they said.
"The whole public sector has been made to feel guilty, like they should be grateful that they are in public service," said Chris Keates.
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