The National Union of Teachers vowed to step up their campaign as the row over pay, pensions and conditions continues.
National strikes will take place in the week beginning Monday 23rd June if "significant" progress is not made in resolving the long-running dispute.
The NUT have also said they will not rule out more than one day of strike action, with further action in the autumn still a possibility.
The strikes could leave thousands of school children across the country facing the prospect of school closures and disruptions to lessons.
For childcare cover contact Education Matters. £20 per child for a strike day.