Unions representing almost 20,000 second level teachers are to ballot their members in September on industrial action over pay and conditions.
The Association of Secondary Teachers, Ireland (ASTI) and the Teachers' Union of Ireland (TUI) will take joint action if no agreement is reached in talks with the Government before the start of next school year.
Talks with representatives of the Departments of Education and Finance have been continuing since the unions rejected the previous offer last March.
But the largest union, the Irish National Teachers Organisation (INTO), voted to accept the Government offer, which it now wants implemented.
A joint meeting of the ASTI and TUI executives this week resolved to draw up a list of possible actions.
