The ASTI is calling on Minister for Education Ruairi Quinn to "listen to teachers" when it comes to proposed changes to the Junior Cert.
Some 180 members of the teaching union's central executive council are meeting in Dublin this afternoon to decide if they will ballot their members.
Minister Quinn plans to remove external examiners from the junior cycle in exchange for continuous assessment carried out internally in schools by teachers.
The TUI has already voted in favour of balloting their members.
The ASTI has raised concerns that the teacher's role as a facilitator to students will be compromised if they are to also act an examiner.
General secretary, Pat King says that teachers have not received enough training for this new system to be implemented by September.
"Schools and teachers are unprepared," he said. "There is minimal amount of training and preparation for teachers.
"Teachers want to do this right, and the preparation they are being provided with, the training, the in-service, is paltry."