Teachers are raising the threat of industrial action over public sector spending cuts in what could become a summer of discontent for a new Government.
A priority motion to be debated at the National Union of Teachers (NUT) annual conference in Liverpool this weekend calls for a joint campaign with the TUC and public sector unions, including strikes if necessary, to oppose cuts to services, threats to pensions and pay freezes.
It calls on the union to "reject plans outlined by all major parties for cuts in vital services which will impact on the children we teach".
It will be seen as the first shot in what is likely to be a huge battle for whichever party wins the upcoming general election over public sector pay, jobs and cuts in services.
Speaking as the conference began, NUT deputy general secretary Kevin Courtney said: "I think lots of teachers are very worried about the possibility of funding cuts."
NUT general secretary Christine Blower said: "One of our concerns is what anyone who is chancellor thinks of as frontline services is not the same as what we think of as frontline services."
Schools Secretary Ed Balls has asked schools to save around £1 billion although he has promised to protect frontline services. And the Conservatives have said they will only protect spending for the NHS and international development.
Ms Blower insisted strikes would not be the first course of action.
"We know this is an action of last resort, the fact is there are some times where you may have to do this."
This weekend's resolution comes after seven days of strikes by British Airways cabin crew in a dispute over jobs and cost-cutting which is still unresolved, and three days of strikes by civil servants in a row over redundancy pay, which will be followed by more action in the coming weeks.
There has also been a threat of strikes on the railways, which was dramatically called off yesterday when Network Rail was granted an injunction suspending Tuesday's four-day walkout after successfully arguing that the Rail Maritime and Transport's (RMT) strike ballot was flawed.
Since last Thursday, more than a million local council workers have been facing a year's pay freeze, which will be opposed by unions.
The NUT's motion argues that many essential services have already been cut, or are at risk, and cannot afford to be cut further.
It calls on the union to "reaffirm the view that there should be no cuts in education funding or school budgets which could lead inter alia to a possible increase in non-teacher qualified personnel substituting for teachers and to a worsening of the quality of provision for all members of school communities."
The resolution, which is being brought by the NUT's executive, calls for opposition against public sector pay freezes, saying the TUC has warned that widespread wage freezes would hit the poorest workers and hindered economic recovery.
The NUT last took strike action in April 2008 in a row over pay. They were joined by members of the University and College Union (UCU) and the Public and Commercial Services Union (PCS).
The current three-year pay deal for teachers ends next year.