The plans for Newport College were at an advanced stage with works expected to commence later on this year.
However local Councillor Fiona Bonfield says funding pressures have led the Department of Education to defer works there and at 57 other school projects across the country.
She says Newport College is bursting at the seams with increased enrolments over the last number of years.
“This additional accommodation was approved a couple of years ago and we had progressed really well with the Department on it. There was talk that this work might start later on in the year but now we’ve been told its been stalled so not good news for the school because it really is at capacity.
“For the last couple of years the enrolment has grown significantly which is great for the school an a lot of work has been put in to grow it. I suppose the town of Newport has expanded over the years as well so this has added to the enrolment increasing.
Education Minister Norma Foley says the Newport College project will remain a “priority for delivery.”