Preparations for Communions and Confirmations should only take place outside school hours, a new report says.
The recommendation comes from the Forum on Patronage and Pluralism, which was established by Minister for Education Ruairi Quinn with a view to ensuring that primary education reflects the needs of Ireland's diverse population.
The authors have called for a review of the Rules for National Schools.
The group, chaired by former NUI Maynooth education professor John Coolahan, said that while there was a place for education in religion in schools, faith formation including preparation for sacraments should not be part of the school day.
"The advisory group recommends that sacramental preparation, or education for religious rites or other belief systems, should not encroach on the time allocated for the general curriculum," the report states.
The group advised the National Council for Curriculum and Assessment (NCCA) to develop a new curriculum for education about ethics, religion and beliefs (ERB) for all schools.
It remarked that a new set of guidelines on ERB would be of particular benefit to children who do not participate in religious programmes in denominational schools.
"They may go through their primary schooling without any ERB and ethical education. For these children, the proposed programmes in ERB and ethics are of central importance," the report says.
It is recommending that around 50 schools be moved from the control of the Catholic church -- and handed over to new patrons.
The Forum on Patronage and Pluralism says faith formation should be taught outside of school hours.
The forum says divestment should take place on a phased basis, beginning with Catholic churches in 47 catchment areas already established.
At present, almost 90pc of Ireland's 3,300 primary schools are under Catholic patronage.
The report noted that in areas where new patronage options are unlikely, denominational schools should be more accommodating of a diverse population.
The forum suggested that the equality law be amended.
This law currently allows denominational schools to give preference to children who belong to a particular faith.
The report also called for a review the Rule 68 or the Rules for National Schools, which describes religion as the most important subject in the curriculum.
It said that religious artefacts displayed in schools should not be confined to one faith and that the morning prayer as well as the Angelus be replaces by communal prayers that are respectful of the beliefs of all pupils.