Teachers will back a major escalation of their strike action over Education Secretary Michael Gove's school reforms by threatening further nationwide walkouts from schools in the summer term.
Delegates to the National Union of Teachers' annual conference in Brighton will be urged to back an emergency calling for further strikes throughout England and Wales at the end of June followed, by a programme of more strike action in the autumn.
The motion deliberately makes it unclear how long the strike action will be, leaving the door open for a longer stoppage than the one-day strikes previously planned in their protest over Mr Gove's attempts to introduce new performance related pay measures, increase pension contributions and extend hours to allow all state schools to operate from 8am to 6pm.
Today's conference will hear demands from left delegates to ratchet the strike action up even further and commit the union to staging two days of national strike action throughout England and Wales during the summer.
The strike moves, virtually certain to be passed by the conference - possibly unanimously - will mean hundreds of schools will close and thousands more being partially affected by walkouts and sending children home.
The timing is deliberately pitched to coincide with the ending of the GCSE and A-level exam season, although there are a handful of papers in maths, physics, religious studies and health and social care in the first two days of the week beginning 23 June, which has been selected as the day to start the industrial action. Union leaders said they were anxious to avoid hitting exams.
The announcement of the emergency motion coincides with a poll of 1,526 parents conducted by YouGov for the NUT, which shows Mr Gove's standing amongst parents has dipped to a low of just three percent "totally trusting" him to be in charge of running the state education system. 52 per cent said they did not trust him at all.
Christine Blower, general secretary of the union, said talks with civil servants over the dispute had failed to make any progress - and she urged Mr Gove himself to take the lead in discussion with unions after the Easter break.
She said evidence from the YouGov report that stated two thirds of parents (65 per cent) believed teachers had a democratic right to strike and almost half (49 per cent) agreed with most of the unions concerns about the Government's education policies,
She acknowledged, however, that "it is actually in the nature of industrial action that you do it because you want to cause inconvenience, because you want to bring it to others' attention".
Kevin Courtney, deputy general secretary of their union, added: "We don't want to strike in the summer and we don't want further action. We want a solution." He stressed the strikes could be called off if there was progress in talks.
The National Association of Schoolmasters Union of Women Teachers, which is also involved in the dispute with the Government, is also unlikely to rule out further industrial when it debates the issue on Sunday. The union did not join the NUT in a one-day national stoppage last month because it believed some progress had been made with the profession's pay review body turning down a plea from Mr Gove to scrap regulations which forbade teachers from undertaking a range of administrative duties around the school such as collecting dinner money and invigilating exams.
Today's emergency debate is one of two which will take place over the Easter weekend at the NUT conference; the second will call for support for strike action over threats of job cuts in the country's sixth form colleges.
Union leaders are incensed that the Government has sanctioned spending £45 million on a new elitist free school offering sixth form education in Westminster. The school, jointly sponsored by the Harris Federation academy chain and leading independent school Westminster will offer 500 of the brightest young people from poor families a place.
However, the spending coincides with swingeing cuts to existing sixth form budgets which has seen some have to drop subjects like maths and modern foreign languages at A-level.
Ms Blower said: "The [existing] sixth form colleges have got more kids into Oxbridge than independent schools - sixth form provision in London is fantastic. We don't need this £45 million spent on this super selective school. It is appalling to see the money spent in this highly elitist way."
A spokesperson for the Department for Education said strike action would "damage the reputation of the profession".
She added: "Ministers have met frequently with the NUT and other unions and will continue to do so. Strike action will only disrupt parents' lives, hold back children's education and damage the reputation of the profession."