Officials from a major union representing school support staff are due to hold crisis talks today to discuss industrial action over the Government's decision to axe its national pay body.
Unison - which represents 200,000 teaching assistants, school dinner staff, caretakers and administrators - will announce whether it is to hold a ballot for action this weekend.
If the majority of Unison members are involved in strike action it could be enough to bring many schools to a standstill - even without the support of the GMB or Unite unions.
In previous strikes, special schools have been particularly affected as they are heavily dependent on support staff. In the 2008 strike over pay, headteachers were forced to clean toilets and days were curtailed for all but the most vital exam classes in many schools.
Support staff unions are furious at the Government's decision to axe the School Support Staff Negotiating Body (SSSNB), which has only just begun its work creating a fairer national framework for pay. Ministers said the body "did not fit well" with its priorities for greater deregulation of pay and conditions.
But unions say the body is vital to protect some of the lowest paid workers in schools.
Christina McAnea, head of education at Unison, said the decision shows that the Government considers support staff "expendable".
She called on Education Secretary Michael Gove to protect support staff's pay and conditions as schools gain more freedom on pay through the academies boom.
"We want guarantees that workers will have their pay and conditions protected, that training and advice will be provided and new starters will get good treatment and not be put on worse contracts than existing staff," she said.
Ms McAnea said she is interested in the work of the SSSNB being absorbed into the School Teachers' Review Body, which advises the Government on teachers' wages. "But we haven't heard anything from the Government on that," she said.
A Government statement on the abolition of the SSSNB confirmed: "(It) does not fit well with the Government's priorities for greater deregulation of the pay and conditions arrangements for the school workforce."