Members from the Lewes Wealden and Eastbourne branch of the National Union of Teachers will go on strike on Wednesday March 26.
The NUT said it represented more than 80 per cent of all teachers in Brighton and more than 60 per cent of all teachers in East Sussex.
Rallies and protest marches are being held in Brighton, Eastbourne and Hastings.
Phil Clarke, Secretary of Lewes, Eastbourne and Wealden NUT said: “Teachers dedicate themselves to their jobs and striking is never easy.
“This strike is about not only our own pay and conditions but is also the long term future of education for all children. “School holidays, most of which are already spent working do not make up for 60 hour weeks which the government’s own survey reveals is the norm for teachers.
“Working such excessive hours until 68 years old while pay is forced down is already causing a recruitment crisis that is only going to get worse. Parents unfortunately put out by this strike should lay blame solely with the government and Michael Gove.
“He refuses enter into meaningful talks and leave us with no choice if we are to make ourselves heard.”