The teachers are calling for equal pay for equal work
Industrial action is very likely amongst secondary teachers, according to the ASTI.
The result of their ballot is expected today, which could lead to schools closing this autumn.
The union is unhappy about pay levels for new teachers and will hold a protest outside the Dáil this evening.
The protest will be attended by new and recently qualified teachers, and their teacher colleagues, from schools in the Dublin area.
They are calling for equal pay for equal work.
ASTI teachers are currently on three different pay rates - depending on when they entered the profession.
New and recently qualified ASTI teachers are on starting salaries which are 20% below the 2010 teachers’ starting salary.
The president of the union, Ed Byrne, says there can be no compromise.