The Teachers' Union of Ireland says a proposed new pay deal, drawn up between unions and Government earlier this year, will lead to an even greater shortage of teachers than is currently the case.
The TUI is recommending rejection of the Public Service Stability Agreement 2018-2020, which allows for further phased restoration of the pay cuts imposed during the financial crisis.
The union says it has received reports from some colleges that there has been a 50% drop in the number of applicants going on to the teacher-training qualification.
Speaking on RTÉ’s Morning Ireland, TUI President Joanne Irwin said they believed it was for a number of reasons.
She said the fact that the Masters in Education, which is required to qualify as a teacher, has been extended to a two-year programme is affecting the number of teachers qualifying.
"It used to be a one-year training programme. That's an additional €9,000 for the additional year as well as the money that you're losing that you could be earning in that year," she said.
Ms Irwin also said the union believes the shortage is down to the differentiated pay scales that are now in operation and with the demographics going the way they are it is going to rise year on year until 2025 when "we reach our peak".
She said the union wanted teachers in a staff room to be on the same salary scale.
Ms Irwin said there is already anecdotal evidence of a severe shortage of teachers in certain subjects, such as Irish and home economics.
She said home economics graduates are going into industry because they can get a permanent job straight-off with a better salary scale.
Ms Irwin said the shortage was leading to teachers unqualified in the particular areas having to fill in and leaving an inconsistent learning environment for students.