The Government is being urged to hold talks with union leaders in a bid to avert a planned strike by teachers in a row over pay and conditions.
Members of the National Union of Teachers (NUT) will walk out on July 5 in England after voting by more than 9-1 in favour of industrial action.
The union said its demands were to increase funding to schools and education, guarantee terms and conditions in all types of schools, and to resume negotiations on teacher contracts to allow workload to be addressed.
In a letter to Education Secretary Nicky Morgan, the union called for "meaningful" discussions to tackle issues it said were negatively affecting education.
Acting general secretary Kevin Courtney said: "No teacher finds taking strike action easy but the situation in our schools needs to be urgently addressed. School budgets are being cut to the bone. The effect on children's education is clear. Class sizes are going up, subjects are being removed from the curriculum, especially in the Arts, while teaching posts are being cut or not replaced.
"Teachers' terms and conditions are being deregulated and worsened through the academy programme. Head teachers are spending time on school negotiations which should be spent on education. This is unnecessary, time wasting and ineffective. There is no evidence it leads to better results in schools and is fuelling the teacher retention and recruitment crisis."
An Education Department spokesman said: "We are already in regular and constructive talks with the National Union of Teachers on pay and conditions. It is disappointing that they have chosen to continue with this unnecessary and damaging strike, which less than a quarter of its members voted for, despite our ongoing commitment to formal talks addressing their concerns.
"Industrial action causes disruption to children's education, to their parents who have to take time out of work to arrange childcare and also damages the reputation of the profession. We urge the NUT again not to proceed with this action and to work with us to resolve their dispute at the negotiating table instead of playing politics with children's futures."