Teachers and students from Leinster College are to hold a protest in Dublin in the next hour this morning.
The English language college on Harcourt Street, closed its doors without warning on Tuesday.
A notice posted on the door of the college said the school will not re-open until next month - because of a "weak financial situation".
However, the staff and students say they do not believe it will re-open at all.
It is the latest international school to get into difficulty in recent months. SIPTU said staff at the college have gone without pay in recent months.