Teachers' unions planning autumn strikes in England
The two biggest teachers' unions are threatening a national one-day strike in England before Christmas in a row over pay, pensions and workloads.
But the NUT and NASUWT have held back from announcing a date and are calling for talks rather than "megaphone diplomacy" with the government.
The teachers' unions have given dates in October for their continuing campaign of rolling regional strikes.
Education Secretary Michael Gove said: "I unhesitatingly condemn this action."
There will be regional strikes on 1 October in the east of England, the Midlands, Yorkshire and the Humber region and on 17 October in London, North East, South East and South West.
There will not now be any regional strikes in Wales.
Call for talks
Teachers have accused the government of "reckless and irresponsible behaviour" and say that Education Secretary Michael Gove has refused to engage in meaningful negotiations.
The government says such strikes will disrupt pupils' learning, inconvenience parents and damage the reputation of teachers.
In a speech in London on Thursday, Mr Gove rejected claims that reforms had damaged teachers' morale, saying that teaching "has never been more attractive, more popular or more rewarding".
He said he would meet teachers' unions "any time, any place, anywhere", but accused their leaders of pursuing strike action for "ideological reasons".
Mr Gove said that "teachers have better pensions than the majority in the public and private sectors".
Labour's Stephen Twigg said the coalition was "undermining teacher professionalism by allowing unqualified teachers to be employed in schools on a permanent basis".
Mr Gove called on Labour to condemn the strike call.
The teachers' union leaders, announcing strike dates, say they want to negotiate on changes to pay and pensions.
Under reforms, set to come into effect from this autumn, pay will be linked to performance in the classroom and head teachers will have greater flexibility over salaries.
Teachers have protested against reductions to their pensions.
The regional strikes announced on Thursday are a continuation of a rolling series of strikes launched in the summer term.
The teachers' unions say they will decide on a national strike after the next regional strikes in October.
Christine Blower, general secretary of the NUT, said: "At the start of the new academic year, the last thing teachers wish to be doing is preparing for further industrial action.
"With pay, pensions and working conditions being systematically attacked and an education secretary who refuses to listen or negotiate teachers now have no other choice."
Chris Keates, general secretary of the NASUWT, said the teachers' unions would meet the government "any time, any place" and that parents would understand that teachers needed to protect their pay and conditions.
A Department for Education spokesperson said: "It is disappointing that the NUT and NASUWT are striking over the government's measures to allow heads to pay good teachers more.
"In a recent poll, 61% of respondents supported linking teachers' pay to performance and 70% either opposed the strikes or believed that teachers should not be allowed to strike at all."