Up to 3,600 unqualified people were employed as teachers in the past year as schools struggled to fill gaps for short-term absences.
The numbers show, for the first time, the full scale of the challenge facing schools unable to find qualified or registered teachers to fill in for career breaks and maternity or sick leave.
Schools are entitled to employ individuals without any formal qualification or registration to teach in the classroom as a measure of last resort. However, they are limited to teaching in a particular school for a maximum of five days.
In all, these individuals provide cover for 32,000 teaching days during the 2016/2017 academic year.
Some schools say this is causing severe disruption to students who are faced with a new, unqualified or unregistered teacher every week.
Joan Burton TD, Labour’s education spokeswoman, said: “I talk to principals who are constantly at the end of their tether in relation to being able to access qualified staff when they need replacements for cover.
“The Minister for Education seems to be in denial about this. I think they only now appreciate there is a major problem – but we need a plan to address this, and we need to do so urgently.”
Independent TD Maureen O’Sullivan, a former teacher who chairs the board of management of a school on Dublin’s northside, says one class is suffering due to “constant changes” in teachers.
“We have been unable to fill the position, so we have no choice. When a new person comes in, there is catch-up. It makes it extremely difficult. The key to teaching is the relationship between the teacher and pupil. If you have constant change, all of that gets disrupted.”
The Department of Education said recruitment and appointment of teachers to fill posts was a matter for the individual school authorities.
Schools were required to employ “appropriately qualified and registered teachers”, the department said in a statement.
However, an unregistered person may be appointed “where a school has made all reasonable efforts to appoint a registered teacher in accordance with the normal appointment procedures and no registered teacher is available to take up the position in question”.
The department confirmed that any unregistered person who is a teacher must be vetted for child-protection reasons.
It confirmed that unregistered individuals may not be paid from public funds for a continuous period of more than five consecutive school days.
Teacher shortages appear to be linked to the volume of young teachers who are taking career breaks or emigrating to work in the Middle East, where salaries can range from €2,000 to €5,500 a month tax-free.
At second level, a shortage of teachers in key subjects such as science and languages seems to be linked to job prospects available to graduates in other sectors of the economy.
Minister for Education Richard Bruton has sought to ease some of this pressure on recruitment by relaxing work restrictions for retiring teachers, along with increasing employment limits for teachers on career breaks.
He also pledged to examine whether free third-level teacher education courses should be offered to homemakers with qualifications in key subject areas.
Mr Bruton has noted that some 2,300 new teachers were successfully recruited in the last academic year, while the process of filling a further 2,900 posts in the current year is almost complete.