ASTI members have voted overwhelmingly to recommend a rejection of the Labour Court deal aimed at ending their long-running dispute.
Delegates voted by over three-to-one to issue a 'no' recommendation with next week's ballot paper.
The ASTI also voted on a motion of whether to stop industrial action for this year's exams.
The outcome of the vote shows that the organisation cannot give any assurances that the Leaving and Junior Cert examinations will not be disrupted.
ASTI General Secretary Charlie Lennon said today that further industrial action cannot be ruled out.