Travellers who booked to travel on the WB Yeats ship this summer now have to look for another means of transport after the company cancelled the planned trips.
Irish Ferries also said the cancellation was due to further delays in constructing the vessel by German Flensburger Schiffbau-Gesellschaft & Co KG.
The ferry had to start sailing in July 2018 but all trips will now start between Ireland, France and the United Kingdom in September.
Clients have been contacted about the cancellations and offered alternative travel options.
Previously, Irish Ferries was forced to cancel July itineraries for WB Yeats in April when they were told by Flensburger Schiffbau-Gesellschaft of the initial delay.
The earlier cancellation impacted around 2,500 bookings, but the company said 95% of those swtiched to MS Oscar Wilde.
Irish Ferries revealed that about 6,000 bookings would be impacted by the latest cancellation (some 19,000 passengers).