The largest secondary teachers union says its members will help students prepare for the delayed Leaving Cert.
The ASTI faced criticism over the weekend because it released a statement saying "no teacher will be required to do anything" and said the proposal for two weeks of class time before the state exams "cannot be enforced".
However, after discussions with its members, it says teachers have given support to students.
ASTI president Deirdre McDonald says the union's approval of the proposal was never in doubt.
"There's no evidence of that throughout the country, so that is a given.
"What we wanted to do was consult with the membership, and we wanted to find out what were the issues before anybody commits.
"Good decision making, it's one of the things we teach in school, and it's about full knowledge and full consent."
