Minister for Education Batt O'Keeffe has said he regrets a decision by teachers' unions to instruct members not to cover for retired teachers who have not been replaced.
Minister O'Keeffe said the action will make it more difficult for schools to manage in these difficult times.
The minister made the comments after an Irish Independent story claimed that secondary schools could be forced to close in September because of the union move.
The move by teachers is an escalation of their work-to-rule against public sector pay cuts.
The newspaper says that some '900 assistant principals and hundreds of special duties teachers have already retired this school year and have not been replaced.'
However, Mr O'Keeffe said that the hiring moratorium on the filling of vacant promotion posts is being applied across the public service generally.
He said that education is being treated more favourably than other areas, such as the civil service. Schools are still recruiting new teachers to fill vacancies and only promotion posts are being restricted.
Minister O'Keeffe said that in these extraordinarily difficult times we all need to pull together.
Mr O'Keeffe acknowledged that teachers have a strong commitment to their pupils.
He said that the Government's responsibilities to pupils required that 'difficult decisions be taken to secure our longer term well-being'.
Managers of the country's vocational second level schools say the decision not to cover for retired teachers is regrettable.
It says many more posts of responsibility will be vacated over the summer months as more teachers retire.
It has called on the Government to assess the impact of the moratorium on schools before the summer holidays.
