Teachers in England are to stage fresh strikes in their long-running dispute over pay.
Members of the National Education Union (NEU) will walk out on July 5 and 7, causing disruption to schools in the current term.
The NEU is currently re-balloting its members to see if they want to continue taking industrial action for the rest of the year.
The other education unions - ASCL, NAHT and NASUWT - are also balloting their members for strikes over pay and funding for teachers in England.
The unions warned of coordinated action in the autumn term if there is no settlement to the dispute.
Dr Mary Bousted and Kevin Courtney, joint general secretaries of the NEU, said it was within the grasp of Education Secretary Gillian Keegan for the action to be halted.
"Time and again the National Education Union, alongside its sister unions, have called for the Education Secretary to get around the negotiation table to settle this dispute for a fully-funded teacher pay increase. Time and again our calls have fallen on stony ground," they said.
"The Education Secretary refused to re-enter negotiation on the grounds that she and her department were waiting for the publication of the School Teachers' Review Body's (STRB) recommendation on pay."
The NEU said the minister had received the body's report and recommendations, but would not comment on speculation that it was suggesting a 6.5% pay rise.
The union leaders said they were worried that the Government was contemplating not implementing the report or not funding it properly.
They added: "Gillian Keegan also says that she will publish the report in her own good time, which by her department's recent record will be at least another month.
"This causes huge uncertainty for schools and is hugely disrespectful to headteachers. None are able to properly plan for next year.
"Unlike her counterparts in Scotland and Wales where the pay disputes have been settled, this Education Secretary has wilfully turned her back on teachers in England.
"No one wants to take strike action but when faced with an Education Secretary who clearly has no interest in settling this dispute, teachers are left with no option.
"Gillian Keegan could avoid the strikes in July by publishing the STRB report, entering substantive talks with us and the education unions ASCL, NAHT and NASUWT to find a settlement on its response to the report, its funding and this year's pay rise."
