The Irish Travel Agents Association says hundreds of people have been forced to cancel or delay holidays over delays getting their passport.
The Passport Office is currently dealing with a backlog of around 95,000 applications.
The ITAA has called for the passport offices in Cork and Dublin to reopen immediately to address the problem.
Chief executive and Cork travel agent Pat Dawson says many holidaymakers are being forced to change their plans.
"Certainly they're in their hundreds, and they will be in their hundreds over the coming weeks.
"Many people would have deferred holidays, and would have gone on staycations.
"Now when kids go back to school people will be going later in the year, in September and October.
"We do have a good number of bookings for September and October, and there's no way they're going to be refunded by airlines or anyone else."