Members of Atheist Ireland are meeting with the Taoiseach and the Education Minister this evening to tell them their rights are not being upheld.
According to the last Census, 340,000 people said they were not affiliated to any religion.
And atheists point out that the educational needs of their children are not met at primary level where 90% of schools are controlled by the Catholic Church.
"We would not even dream of giving preference to the children of religious families in access to our hospitals," said spokesperson Jane Donnelly.
"But as a republic we have no difficulty in refusing access to children in their only local publicly funded school because they are not the right religion."
"The UN have said the discrimination undermines the dignity of the child - but in this republic, that's what we do all the time."