Schools could be caught in a Catch-22 situation after the largest teacher union said it was prepared to strike if class sizes are increased to ensure non-contact time for teachers.
The threat from the National Union of Teachers comes in a week when most schools succeeded in giving teachers their first official periods of planning, preparation and assessment (PPA) time.
Schools are legally obliged to provide 10 per cent non-contact time for teachers from the start of this month.
All three major classroom unions have threatened industrial action if schools deny their teachers this time out. The NUT, which opposed the workforce deal, said it would also fight any moves by schools to double up classes to free teachers' time.
Both the NASUWT and the Association of Teachers and Lecturers are expected to accept increased class sizes in some cases in return for cuts in teachers' workloads.
Steve Sinnott, general secretary of the NUT, said the union would try to resolve members' complaints directly with schools but that it was "quite possible" they would lead to industrial action.
"If we could not resolve the issue, we would consult members on what action they wished to take - ranging from a grievance procedure through to industrial action," he said.
Guidance on the NUT website says the union wants schools to provide the half-a-day a week by employing more teachers.
The National Association of Head Teachers pulled out of the workforce remodelling process in March because it believed schools could not afford to provide non-contact time.
This week, an overwhelming majority of schools organised PPA time without hitches using a wide range of approaches.
While many are offering teachers a spread of free periods throughout the week, others are giving staff a whole day off once every fortnight.
At Gawthorpe primary in Wakefield, support staff have been covering for teachers by giving St John's Ambulance training and organising gardening lessons on the school's allotment.
Regional union representatives said they had not been contacted about problems, but they said it might take until half-term for concerns to be reported officially.
The Department for Education and Skills continued to insist that only 14 schools had complained of difficulties with providing the non-contact time.
But some teething troubles were reported by teachers on the TES online staffroom forum.
Concerns included complaints that some headteachers were breaking the law by refusing to give newly-qualified teachers extra time off for their induction in addition to their PPA time.
Teachers also report cases in which their heads have not specified in advance when they would receive PPA time.
FREQUENTLY ASKED QUESTIONS ABOUT PPA
Can I spend my PPA time at home?
That is entirely up to your headteacher. Some schools are allowing it, but others are not.
My timetable only tells me when I have free periods. Should it specify when I have PPA time?
Yes. Department for Education and Skills guidance states: "Guaranteed PPA time must be timetabled and provided in blocks of half-an-hour or more in order to provide productive use of time".
I am an NQT. On my timetable I have 10 per cent PPA non-contact time scheduled but no extra NQT non-contact time. Is this right?
No. You have a right to 10 per cent non-teaching time for NQT induction.
You should get PPA time on top of that, so at least 19 per cent of your timetable should be free.
Do I need to plan the lessons for the person who takes my classes during PPA?
There is no onus on you to plan the lessons, but it is advisable to liaise with the person taking your class and give them guidance on the subject matter you want covered.