A school principal has predicted a four-day week for pupils after a senior clergyman described the education system in Northern Ireland as "beyond crisis".
Michael Allen, head of Lisneal College in Londonderry, said the situation for non-selective schools like his is even more dire than that for selective schools.
He was speaking after the call from Church of Ireland Bishop of Derry and Raphoe Ken Good for a political intervention to tackle the crisis.
Addressing the General Synod in Derry, Bishop Good said society was in danger of failing young people unless the "unravelling" of the education system is prevented.
He said: "We have frequently heard the word 'crisis' used to describe the state of education here. I fear, though, it's gone way beyond 'crisis'.
"But little is happening to prevent the fabric of our education system from unravelling.
"We need intervention - urgent intervention - by those with power in our society. We are in danger of failing this generation of young people.
"When it comes to something as important as our education system, failure is not an option."
Mr Allen said schools are on a downward spiral and heading towards a four-day week.
He said: "The general public do not see what the reality is because it isn't affecting them yet.
"If a school is struggling financially, having to cut corners, increase class sizes, cut the curriculum, reduce trips, generally that won't have an impact on parents.
"The goodwill of teachers and staff in schools will cover the lion's share of anything that will see children miss out or suffer.
"But it has now reached breaking point.
"People are now talking about a four-day week, pupils having half days, and if you take a non-selective school like Lisneal the effect of funding is even greater. It is the non-selective schools that are hit first and it is the non-selective schools where arguably the children have the greatest need who are disadvantaged first.
"The entire way schools are funded needs a total review.
"Throwing money at this isn't going to fix it for every school.
"It is going to fix it for the grammar and selective schools who can pick their numbers every year, but non-selective schools can't do that.
"Bishop Good has captured the mood that it is all about to unravel, but it will only be when Mr and Mrs Joe Public have to finish work early on a Thursday or a Friday because there is no school for their child that they are actually going to recognise how serious this is."