Teachers are gearing up for a fresh round of strikes this summer in a long-running bitter row over pay, pensions and conditions.
Members of the National Union of Teachers (NUT) could stage walkouts at the end of June if their dispute is not resolved, it has been announced.
The union is due to debate a priority motion at their annual conference, being held in Brighton, which seeks co-ordinated national strike action in the week beginning Monday June 23, if "significant progress" is not made in ongoing talks with government officials.
The move comes just weeks after the NUT staged a national walkout, and raises the prospect of widespread disruption to thousands of schools in England and Wales in the summer term.
The resolution declares that the NUT's national walkout last month was a success, and calls on the union to continue its Stand Up For Education campaign.
It goes on to say that the union should review the progress made in on-going talks being held with the Department for Education at its May meeting.
The resolution adds: "In the event that significant progress is not being made, seek to co-ordinate national strike action in the week beginning Monday June 23 2014, whilst showing flexibility if other school-based, education and public sector unions are planning action on similar time scales, and whilst being prepared to take strike action alone, as on March 26, 2014."
The latest strike date comes at the end of the summer GCSE and A-level exam season.
Exam timetables show a number of GCSE and A-level maths papers are due to be sat by students on the first two days of that week, in subjects such as maths, physics, religious studies and health and social care. An advanced maths extension paper set by one exam board is also scheduled to take place on Wednesday June 25.
However, NUT leaders insisted that they were not seeking to impact on the exams.
NUT general secretary Christine Blower said: "This week has been deliberately chosen because we believe that there will be no exams beyond those dates.
"We're not, in this motion, seeking to hit public exams, that is not the intention of these dates."
She later added: "Strike action will not disrupt exams. If necessary exemptions can be given got staff who are needed to supervise an exam, but the NUT is looking to take action at the end of the main exam season."
The NUT's resolution does not restrict a walkout to one day only, with the union's deputy general secretary Kevin Courtney saying it has been written to leave "flexibility".
It also paves the way for further strikes in the autumn, calling on the union to agree to develop a programme of action in that term and beyond if there is insufficient progress in the talks.
Ms Blower admitted that a June strike would could disruption, but said that the move could be necessary.
"Of course parents will say this is inconvenient, it is inconvenient," she said.
"It's actually in the nature of industrial action that you do it because you want to cause inconvenience because you're trying to bring your grievances to people's attention.
"That's not to say that we don't regret that we're inconveniencing people, but even though we are inconveniencing people, we still think the balance is about 70-30 of those people who think that we are right, and actually there comes a point where you do have to do this."
The NUT's motion also instructs the executive to continue its campaign through other means, such as with a parliamentary lobby on June 10, participation in talks and preparing for a national demonstration in London on June 21.
Ms Blower said: "We're putting together the fact that we believe this is a significant campaign, and goes on over a period of time.
"But we have, in theory, negotiations going on with government in the period as soon as we get back from conference, between then and when that first June date occurs, so clearly, we will be expecting to go to those negotiations and to engage with them."
She added: "We do want to engage with that process. We want Michael Gove and David Laws to engage with the process, and we can see some things which they could agree which would mean that moving into the autumn, we would not be setting further dates for industrial action."
The NUT's bitter dispute, which has been ongoing for more than two years, focuses on three issues - changes to pay, pensions and workload.
Last year, the union staged a series of regional strikes with the NASUWT teaching union. Between them they represent the vast majority of teachers.
A proposed one-day national walkout in November by the two unions was called off and the NASUWT did not take part in last month's walkout.
The NASUWT is due to discuss its strategy for industrial action at its annual conference in Birmingham on Sunday.