The Irish National Teachers' Organisation (INTO) is calling on the Minister for Education to extend primary schools' Christmas holidays to the end of next week at the earliest as Covid-19 cases continue to grow.
Primary schools are due to reopen on January 6th.
The Government has so far resisted attempts to close down schools.
General Secretary of the organisation John Boyle said it comes in the context of an alarming increase in Covid-19 cases and the emergence of a new variant of the virus which he says affects children.
He said the number of confirmed cases in the schools has grown at an alarming rate in the last fortnight with nearly 700 primary school children testing positive in the 14 days before schools shut for the holidays
In a letter to Norma Foley, Mr Boyle said an extension of the school closures until the end of next week would give school boards of management time to put enhanced measures in place prior to the beginning of term.
“The INTO remains strongly committed to supporting our 42,000 members in safe workplaces, as they endeavour to teach and support the wellbeing of their pupils at school where children undoubtedly benefit greatly,” said Mr Boyle.
“However, it is now becoming very clear that the ability of schools to operate normally is likely to be seriously impaired due to the higher numbers of staff and students who will need to self-isolate and/or restrict movement in the weeks following Christmas,” he added.
Cabinet is meeting today to discuss bringing in full Level 5 restrictions but it's understood that the Government's stance on schools remaining open remains unchanged.