Campaigns are under way in five towns around the country calling on the Department of Education to reverse a decision to limit enrolment at multi-denominational schools in the towns to just 13 new pupils each next September.
Five schools in Trim, Tramore, Tuam, New Ross, and Castlebar have been joined by local parents who have been affected by the decision.
They are holding public meetings and lobbying the Department of Education and local politicians.
The schools all say their enrolment figures for September show that demand from parents is far greater than 13 pupils.
Parents who have enrolled their children for next September say they are being singled out and discriminated against because no other schools have been restricted in this way.
The schools are all run by patron body Educate Together and were all established over the past two and three years to meet local demand for diversity.
Prior to their establishment, the only option for parents in four of the five towns was Catholic primary education. In a fifth town, there is also one Church of Ireland school.
In a statement on the issue, the department said it needed to "preserve a balance among all schools in an area" and ensure that one school was not expanding at the expense of another. It also cited "scarce capital funding".
It referred to surveys carried out four and five years ago, which it said found that in the majority of areas the level of parental demand indicated that schools of "up to half a single stream" were needed.
Half a single stream equals 13 children. A full stream is normally 26 children. The phrase "up to half a single stream" was highlighted in bold in the statement.
However, the statement failed to make clear that in the case of three of the five towns in question, the surveys found that the opposite was the case, that there was demand for schools of "at least half" of a single stream.
The statement also failed to mention that in the case of all of these five towns the department's surveys found that "taking account of likely long-term requirements, accommodation options for a full stream of provision should be considered".
The department said it is considering a request from Educate Together that the restrictions be withdrawn.