The future of Stena Line services in Dun Laoghaire is uncertain as there are growing fears the ferry operator may pull out of the harbour in the long term.
Earlier this month, Stena announced it would not run its high-speed ferry service between Dun Laoghaire and Holyhead in Wales over Christmas for "commercial and operational reasons".
There are rising concerns that the service plans to pull out of Dun Laoghaire altogether and that it doesn't plan to resume the service it normally operates from the port during the summer.
Sources said that this could cost the harbour company €7m.
However the ferry operator said in a statement to the Herald that talks are continuing in relation to the service.
"In recent years Stena Line has deployed the HSS for a few days over the Christmas holiday period on its Holyhead-Dun Laoghaire service," he said.
"For commercial and operational reasons the company has decided not to reactivate the vessel this year for the short Christmas holiday period.
Customers who have already booked on the service will be accommodated on other sailings best suited to their travel requirements.
Stena Line is currently engaged in ongoing discussions with Dun Laoghaire Harbour in relation to the provision of a seasonal fast craft service in 2015 and this remains the situation." It added that it would not comment on speculation about the estimated cost to the business.
"Stena Line's commercial arrangement with Dun Laoghaire Harbour is a confidential arrangement between both organisations," the company said.
Stena's withdrawal would be a major blow to Dun Laoghaire Harbour.
Dun Laoghaire Harbour would not discuss the financial details of their agreement on the grounds it is commercially sensitive.