The principal of a Carlow Educate Together school says an apparent solution to the substitute teacher shortage has not seen any extra staff on the ground.
Simon Lewis, who also presents the 'If I were the Minister for Education' podcast, says he received a letter on Monday from the Department of Education.
However he says the claim of a resolution is "very debatable".
Education Minister Norma Foley previously said measures had been put in place to ensure schools always have access to substitute teachers.
She said substitution panels had been extended to help plug gaps.
But Mr Lewis has said his school, which educates over 400 pupils, did not have one day last term with a full cohort of staff.
He told The Hard Shoulder it all looks good on paper.
"There's claims that we now have an extra 100 teachers in the system, and they've relaxed some of the restrictions on teachers who might be job sharing or on career breaks.
"But on the ground, that's not translating into any extra substitutes, unfortunately".
He says colleagues of his have found the same issue.
"They just aren't there - and the same with all my colleagues, we keep in touch with each other on a daily basis just to keep each other updated.
"It's the same story and I think it's going to continue to be that way".
Mr Lewis says he believes the claim of 100 extra teachers is from people being moved around.
"Any teacher... that was available has certainly been tapped up by principals, whether they're on this substitution panel or not.
"Effectively I think what's happening is there's 100 jobs that are being created, are effectively just going to be shifted from another place to this place.
"So in effect there is a zero net result".
He says this will leave schools in the same place as before.
"I suppose this leaves us in the same place we were before the mid-term break.
"We're already short of substitute teachers, and with rising cases a lot of teachers are becoming ill or close contacts.
"Mid-term break sort of acted as a circuit break in a way; so I imagine over the next few weeks we're going to find ourselves under pressure again.
"And perhaps there will be some schools having to close down classes - particularly smaller schools, where they don't have as many adults in the building to cover", he adds.
