The executive of the ASTI will meet tomorrow to decide its next step after rejecting the latest junior cycle proposals.
Members of the country's largest secondary teachers union have voted against the proposals by 55% to 45%.
The Education Minister Jan O'Sullivan has said she is "deeply disappointed" at the decision.
Secondary teachers in the TUI have voted to accept the proposals by more than two to one but the ASTI said teachers were not split on the issue.
“We are of course pro-reform. Teachers are always involved in change we are constantly involved in change,” ASTI President Máire Ni Chiarba said.
“We don’t need any documents to tell us we have to be involved in change and we will have to see where we move from here...
"We are a democratic organisation and when our members have spoken it is incumbent upon us to listen to them.”