Religion teachers have criticised as "misleading" and "negative" a circular published earlier this week by the Department of Education, which instructs State schools to make religion an optional and not a compulsory subject for students.
In a letter to Minister for Education Richard Bruton, the Religion Teachers' Association of Ireland said parts of the communication were "misleading and ungenerous".
It said it undermined 20 years of progressive work by religion teachers, principals and boards of management across the post-primary school sector.
While acknowledging that parents should have the right to request their child does not participate in religious education, the letter criticises what it calls a "negative tone" in the communication to schools, as well as its failure to state positively the opportunities offered by the subject.
The association has also accused the Department of Education of spreading "misinformation" about the subject "by seeming to equate religious education with religious instruction in a particular faith".
The circular from the department said the State developed curriculum for religious education "currently also serves to meet the religious instruction requirements of the Catholic Church".