Britain's two biggest teaching unions forged an alliance on Monday to beat back the government's "fierce and savage attacks."
The NUT and NASUWT have signed a "joint declaration of intent" that threatens co-ordinated autumn strikes unless the Con-Dems stop their onslaught on teachers' jobs, pay, pensions and conditions.
Together they speak for 85 per cent of teachers in England and Wales.
NUT leader Christine Blower said Education Secretary Michael Gove - "the least popular we have ever had" - was putting "massive obstacles" in the way of teachers' work and hurt students' education.
Ms Blower and NASUWT general secretary Chris Keates have written to Mr Gove demanding urgent talks about the "enormous threats" to the entire schooling system.
They want Mr Gove to back off and reach a deal with them before the start of the next school year - or they'll strike.
"In the Conservative manifesto they said they would enhance the education system, but in two years we have seen teachers' morale drop to the lowest it has ever been," said Ms Blower.
"The government has sought to undermine teachers since coming to power. The onslaught of attacks and threats to pay, pensions and working conditions cannot continue."
She warned that campaign to defend teachers' pensions is "far from over" and branded Mr Gove's academy plans an "unnecessary waste of taxpayers' money" that is hurting other schools.
The NUT will hold a new ballot for industrial action covering wider issues than the current pensions dispute with the result due in the autumn term.
NASUWT has been taking action short of a strike on pay, jobs, workloads and pensions since last December.
Ms Keates warned of a schools "crisis," with a third of teachers saying they don't feel valued and more than half considering quitting.
"The government's narrative is the denigration of the profession exasperated by a drive to privatise," she said.
"Both unions have campaigned on all these issues. The attacks on teachers are so fierce, so savage and of such magnitude that it is essential to work together to defend the profession."
The unions ruled out suggestions of a merger.
Official inflation figures understate the real extent of rising costs, but even the government's own CPI scheme lays bare the ongoing misery for working people and those dependent on benefits.
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