A new survey shows that most teachers believe plans to reform the Junior Cycle could undermine educational standards.
Outlining the findings, the Association of Secondary Teachers, Ireland (ASTI) said this was not just a knee jerk reaction to change.
It said teachers had profound concerns as to whether the plans would work.
The reform plans centre on the abolition of the Junior Certificate exam.
The ASTI survey of teachers in more than 320 schools found strong opposition to the removal of the State exam.
Teachers also expressed strong concern about the impact of the proposed reforms on the standard of education, as well as equity in the system, and student-teacher relationships.