Fianna Fail's proposing to end the right of schools to prioritise students from certain religions.
It's planning an overhaul of all school admissions, so that schools are obliged to take pupils from their local catchment area if space is available.
The only exception is that schools would first prioritise the siblings of existing pupils - but their religion could not be taken into account, even if the school is run by a religious body.
Their promise comes as the government's own proposals to regulate admissions, through an Admissions to Schools Bill, are set to lapse - as they will not have passed by the time the Dáil is dissolved.
Education spokesman Charlie McConalogue says the measure would work as long as there is enough capacity in schools: