THERE are 600 more primary teachers graduating each year than are needed in schools.
Even with the boom in pupil enrolments, the department predicts a continuing surplus of newly qualified teachers in coming years.
It means that the Exchequer or individual students are spending millions every year on training for posts that don't or won't exist.
The oversupply is causing an annual scramble for available jobs and widespread disappointment for those who don't get them.
It is a source of major concern and discussions have started on how to achieve a more accurate match between graduate numbers and jobs.
Education Minister Ruairi Quinn has asked the Teaching Council, in line with its statutory remit, to advise on the issue.
"The minister is anxious to ensure that forecasting mechanisms are developed to ensure an adequate supply of primary and post-primary teachers with the required qualifications," his spokesperson told the Irish Independent.
But the problem won't be resolved easily. The biggest single teacher-training course for post-graduates is run by the online company, Hibernia College – but because it is a private provider, Mr Quinn has no control over its student intake.
The extent of the surplus and the challenges in sorting it are outlined in material released to the Irish Independent under Freedom of Information legislation.
An internal Department of Education discussion document, prepared last December, predicts that 2,155 new primary teachers will qualify each year.
It sets that figure against an average annual demand for new teacher appointments, estimated at 1,530, reflecting a growth in pupil numbers up to 2018/19.
That is an excess of 625 each year between the number of graduates and the number of available posts.
On the other side of the equation, the document predicts a need for an average of an additional 660 teachers a year to cope with extra enrolments up to 2018/19.
Jobs will also arise through an estimated 770 retirements each year and about 100 other vacancies annually because of deaths or teachers leaving posts.
While there is also a need for about 1,100 teachers to cover for career breaks, and about 3,500 each year to cover maternity and sick leave, these are short-term positions and newly qualified unemployed teachers currently in the system will continue to soak up many of these.
Irish National Teachers Organisation general secretary Sheila Nunan said too many teachers were being trained.
Ms Nunan said that meant that after a huge investment in their professional training, hundreds face at best irregular, part-time employment and at worst unemployment or emigration.
"The practice of allowing student teachers to train at huge expense for jobs that won't exist, in the long term will damage the teaching profession.
"Increasing numbers of unemployed teachers are being forced to look abroad for work.
"There are increasing numbers of teachers competing for any part-time and temporary work that's available," she said.