The Teachers' Union of Ireland has decided to ballot its members on the Government's junior cycle reform proposals.
The ASTI has also announced it will be taking the same course of action.
Both unions said teachers are concerned that the Government is not listening to their calls to slow down the reforms.
Minister for Education Ruairi Quinn has rejected such claims.
He said his department is prepared to resolve issues raised by teachers about the new cycle, which is due to be phased in from next September.