The country's largest second-level teachers union has voted to reject the latest junior cycle proposals.
Members of the ASTI have rejected the proposals by 55% to 45%.
In a statement ASTI President Máire G Ní Chiarba has said teachers do not have faith in the Government.
“Second-level schools and teachers are delivering much more with far less. In this context teachers do not trust the Government to adequately resource and support schools as they implement the significant changes required by the junior cycle proposals,” said Ní Chiarba in the statement.
“Teachers needed far more clarity and detail about how the process will operate in reality.”
Under the compromise solution agreed with the Education Minister Jan O’Sullivan in May, teachers would implement classroom-based assessment - but critically, would not mark their own students for State exams.
The TUI has yet to reveal the result of their ballot.