Letters have been sent out to Essex parents ahead of four days of teacher strikes.
Essex County Council's education directorate has updated parents on the situation regarding the strike action.
The National Education Union (NEU) announced it had reached the threshold to hold industrial action last week. The strike dates are February 1 and March 1, 15 and 16.
The letter to parents warns headteachers may not be able to tell them the school's full arrangements until the morning of each strike day.
This is as headteachers can ask staff in advance who will be striking, however, NEU members do not have to provide this information until the day of strike action.
It says: "Each school in Essex will be affected differently by the strike action depending on the number of staff who are members of the NEU, the number that decide to strike on the dates above and other issues of absence the school may be experiencing such as staff illness.
"Each school will undertake a risk assessment to determine what education provision it may be able to make for your child on the days the strikes will be held."
The council says the Department for Education has asked schools to prioritise attendance for exam year groups, vulnerable pupils and children of critical workers.
The letter adds that headteachers will write to parents nearer the time to outline the arrangements it will be putting in place while strike action is underway.