The forum, announced two weeks ago, will discuss a number of options put forward by Education Minister Richard Bruton, including the outright ban on religion being a consideration if schools do not have enough places for all applicants.
However, such a move would require a range of possible legal changes.
Another option is based on the minister’s concerns around schools giving priority to children from outside the immediate area at the expense of local children of a different faith, or none.
However, it is thought such a move could be the subject of significant opposition from a number of minority religions as well as some Dáil backbenchers.
The forum is part of a broader consultation on the role of religion, and the first of its kind.
Even before the minister announced the initiative, he expressed his view that it was unfair that preference is given by publicly-funded religious schools to children of their own religion who might live some distance away, ahead of children of a different religion or of no religion who live close to the school.
He had also expressed dissatisfaction that parents, who might otherwise not do so, may feel pressurised to baptise their children in order to gain admission to their local school.
As part of the consultation, written submissions were invited and attracted almost 1,000 responses from a combination of individuals, schools and stakeholder organisations.
Invitations were sent to all those who made submissions and approximately 150 people are expected to attend the forum this morning.
The event will only be partly held in public, with a number of roundtable discussions planned after the minister makes an opening address.
Ahead of the event Mr Bruton said: “There are no easy solutions to this problem. The difficulties which arise include constitutional law, administration of the schools system and protection of minority religious groups.”
However, citing the growing number of people who identified as having no religion in the latest census, he said: “Doing nothing is not an option.”
In addition to the “catchment area” option, and an outright prohibition on religious schools using religion as a factor in admissions, another option is a ‘nearest school rule’, allowing religious schools to give preference to a religious child only where it is that child’s nearest school of that particular religion.
There is also the possibility of a quota system, which would allow a religious school to give preference to children of its own religion in respect of only a certain proportion of places.